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RFC2566 - Internet Printing Protocol/1.0: Model and Semantics

王朝other·作者佚名  2008-05-31
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Network Working Group R. deBry

Request for Comments: 2566 Utah Valley State College

Category: EXPerimental T. Hastings

Xerox Corporation

R. Herriot

Xerox Corporation

S. Isaacson

Novell, Inc.

P. Powell

Astart Technologies

April 1999

Internet Printing Protocol/1.0: Model and Semantics

Status of this Memo

This memo defines an Experimental Protocol for the Internet

community. It does not specify an Internet standard of any kind.

Discussion and suggestions for improvement are requested.

Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

IESG Note

This document defines an Experimental protocol for the Internet

community. The IESG expects that a revised version of this protocol

will be published as Proposed Standard protocol. The Proposed

Standard, when published, is expected to change from the protocol

defined in this memo. In particular, it is expected that the

standards-track version of the protocol will incorporate strong

authentication and privacy features, and that an "ipp:" URL type will

be defined which supports those security measures. Other changes to

the protocol are also possible. Implementors are warned that future

versions of this protocol may not interoperate with the version of

IPP defined in this document, or if they do interoperate, that some

protocol features may not be available.

The IESG encourages experimentation with this protocol, especially in

combination with Transport Layer Security (TLS) [RFC2246], to help

determine how TLS may effectively be used as a security layer for

IPP.

Abstract

This document is one of a set of documents, which together describe

all ASPects of a new Internet Printing Protocol (IPP). IPP is an

application level protocol that can be used for distributed printing

using Internet tools and technologies. This document describes a

simplified model consisting of abstract objects, their attributes,

and their operations that is independent of encoding and transport.

The model consists of a Printer and a Job object. A Job optionally

supports multiple documents. IPP 1.0 semantics allow end-users and

operators to query printer capabilities, submit print jobs, inquire

about the status of print jobs and printers, and cancel print jobs.

This document also addresses security, internationalization, and

Directory issues.

The full set of IPP documents includes:

Design Goals for an Internet Printing Protocol [RFC2567]

Rationale for the StrUCture and Model and Protocol for the Internet

Printing Protocol [RFC2568]

Internet Printing Protocol/1.0: Model and Semantics (this document)

Internet Printing Protocol/1.0: Encoding and Transport [RFC2565]

Internet Printing Protocol/1.0: Implementer's Guide [ipp-iig]

Mapping between LPD and IPP Protocols [RFC2569]

The "Design Goals for an Internet Printing Protocol" document takes a

broad look at distributed printing functionality, and it enumerates

real-life scenarios that help to clarify the features that need to be

included in a printing protocol for the Internet. It identifies

requirements for three types of users: end users, operators, and

administrators. It calls out a subset of end user requirements that

are satisfied in IPP/1.0. Operator and administrator requirements

are out of scope for version 1.0.

The "Rationale for the Structure and Model and Protocol for the

Internet Printing Protocol" document describes IPP from a high level

view, defines a roadmap for the various documents that form the suite

of IPP specifications, and gives background and rationale for the

IETF working group's major decisions.

The "Internet Printing Protocol/1.0: Encoding and Transport" document

is a formal mapping of the abstract operations and attributes defined

in the model document onto HTTP/1.1. It defines the encoding rules

for a new Internet media type called "application/ipp".

The "Internet Printing Protocol/1.0: Implementer's Guide" document

gives insight and advice to implementers of IPP clients and IPP

objects. It is intended to help them understand IPP/1.0 and some of

the considerations that may assist them in the design of their client

and/or IPP object implementations. For example, a typical order of

processing requests is given, including error checking. Motivation

for some of the specification decisions is also included.

The "Mapping between LPD and IPP Protocols" document gives some

advice to implementers of gateways between IPP and LPD (Line Printer

Daemon) implementations.

Table of Contents

1. Introduction 8

1.1 Simplified Printing Model 9

2. IPP Objects 11

2.1 Printer Object 12

2.2 Job Object 14

2.3 Object Relationships 14

2.4 Object Identity 15

3. IPP Operations 18

3.1 Common Semantics 19

3.1.1 Required Parameters 19

3.1.2 Operation IDs and Request IDs 20

3.1.3 Attributes 20

3.1.4 Character Set and Natural Language Operation Attributes 22

3.1.4.1 Request Operation Attributes 22

3.1.4.2 Response Operation Attributes 26

3.1.5 Operation Targets 28

3.1.6 Operation Status Codes and Messages 29

3.1.7 Versions 30

3.1.8 Job Creation Operations 32

3.2 Printer Operations 34

3.2.1 Print-Job Operation 34

3.2.1.1 Print-Job Request 34

3.2.1.2 Print-Job Response 38

3.2.2 Print-URI Operation 41

3.2.3 Validate-Job Operation 42

3.2.4 Create-Job Operation 42

3.2.5 Get-Printer-Attributes Operation 43

3.2.5.1 Get-Printer-Attributes Request 44

3.2.5.2 Get-Printer-Attributes Response 46

3.2.6 Get-Jobs Operation 47

3.2.6.1 Get-Jobs Request 47

3.2.6.2 Get-Jobs Response 49

3.3 Job Operations 50

3.3.1 Send-Document Operation 50

3.3.1.1 Send-Document Request 51

3.3.1.2 Send-Document Response 53

3.3.2 Send-URI Operation 54

3.3.3 Cancel-Job Operation 54

3.3.3.1 Cancel-Job Request 54

3.3.3.2 Cancel-Job Response 55

3.3.4 Get-Job-Attributes Operation 56

3.3.4.1 Get-Job-Attributes Request 57

3.3.4.2 Get-Job-Attributes Response 57

4. Object Attributes 58

4.1 Attribute Syntaxes 59

4.1.1 'text' 60

4.1.1.1 'textWithoutLanguage' 61

4.1.1.2 'textWithLanguage' 61

4.1.2 'name' 62

4.1.2.1 'nameWithoutLanguage' 62

4.1.2.2 'nameWithLanguage' 63

4.1.2.3 Matching 'name' attribute values 63

4.1.3 'keyWord' 64

4.1.4 'enum' 65

4.1.5 'uri' 65

4.1.6 'uriScheme' 65

4.1.7 'charset' 66

4.1.8 'naturalLanguage' 67

4.1.9 'mimeMediaType' 67

4.1.10 'octetString' 69

4.1.11 'boolean' 69

4.1.12 'integer' 69

4.1.13 'rangeOfInteger' 69

4.1.14 'dateTime' 69

4.1.15 'resolution' 69

4.1.16 '1setOf X' 70

4.2 Job Template Attributes 70

4.2.1 job-priority (integer(1:100)) 74

4.2.2 job-hold-until (type3 keyword name (MAX)) 75

4.2.3 job-sheets (type3 keyword name(MAX)) 75

4.2.4 multiple-document-handling (type2 keyword) 76

4.2.5 copies (integer(1:MAX)) 77

4.2.6 finishings (1setOf type2 enum) 78

4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX)) 79

4.2.8 sides (type2 keyword) 80

4.2.9 number-up (integer(1:MAX)) 80

4.2.10 orientation-requested (type2 enum) 81

4.2.11 media (type3 keyword name(MAX)) 82

4.2.12 printer-resolution (resolution) 83

4.2.13 print-quality (type2 enum) 83

4.3 Job Description Attributes 84

4.3.1 job-uri (uri) 85

4.3.2 job-id (integer(1:MAX)) 85

4.3.3 job-printer-uri (uri) 86

4.3.4 job-more-info (uri) 86

4.3.5 job-name (name(MAX)) 86

4.3.6 job-originating-user-name (name(MAX)) 86

4.3.7 job-state (type1 enum) 87

4.3.8 job-state-reasons (1setOf type2 keyword) 90

4.3.9 job-state-message (text(MAX)) 92

4.3.10 number-of-documents (integer(0:MAX)) 93

4.3.11 output-device-assigned (name(127)) 93

4.3.12 time-at-creation (integer(0:MAX)) 93

4.3.13 time-at-processing (integer(0:MAX)) 93

4.3.14 time-at-completed (integer(0:MAX)) 94

4.3.15 number-of-intervening-jobs (integer(0:MAX)) 94

4.3.16 job-message-from-operator (text(127)) 94

4.3.17 job-k-octets (integer(0:MAX)) 94

4.3.18 job-impressions (integer(0:MAX)) 95

4.3.19 job-media-sheets (integer(0:MAX)) 95

4.3.20 job-k-octets-processed (integer(0:MAX)) 96

4.3.21 job-impressions-completed (integer(0:MAX)) 96

4.3.22 job-media-sheets-completed (integer(0:MAX)) 96

4.3.23 attributes-charset (charset) 97

4.3.24 attributes-natural-language (naturalLanguage) 97

4.4 Printer Description Attributes 97

4.4.1 printer-uri-supported (1setOf uri) 99

4.4.2 uri-security-supported (1setOf type2 keyword) 100

4.4.3 printer-name (name(127)) 101

4.4.4 printer-location (text(127)) 101

4.4.5 printer-info (text(127)) 101

4.4.6 printer-more-info (uri) 101

4.4.7 printer-driver-installer (uri) 102

4.4.8 printer-make-and-model (text(127)) 102

4.4.9 printer-more-info-manufacturer (uri) 102

4.4.10 printer-state (type1 enum) 102

4.4.11 printer-state-reasons (1setOf type2 keyword) 103

4.4.12 printer-state-message (text(MAX)) 106

4.4.13 operations-supported (1setOf type2 enum) 106

4.4.14 charset-configured (charset) 107

4.4.15 charset-supported (1setOf charset) 107

4.4.16 natural-language-configured (naturalLanguage) 107

4.4.17 generated-natural-language-supported(1setOf naturalLanguage108

4.4.18 document-format-default (mimeMediaType) 108

4.4.19 document-format-supported (1setOf mimeMediaType) 108

4.4.20 printer-is-accepting-jobs (boolean) 109

4.4.21 queued-job-count (integer(0:MAX)) 109

4.4.22 printer-message-from-operator (text(127)) 109

4.4.23 color-supported (boolean) 109

4.4.24 reference-uri-schemes-supported (1setOf uriScheme) 109

4.4.25 pdl-override-supported (type2 keyword) 110

4.4.26 printer-up-time (integer(1:MAX)) 110

4.4.27 printer-current-time (dateTime) 111

4.4.28 multiple-operation-time-out (integer(1:MAX)) 111

4.4.29 compression-supported (1setOf type3 keyword) 111

4.4.30 job-k-octets-supported (rangeOfInteger(0:MAX)) 112

4.4.31 job-impressions-supported (rangeOfInteger(0:MAX)) 112

4.4.32 job-media-sheets-supported (rangeOfInteger(0:MAX)) 112

5. Conformance 112

5.1 Client Conformance Requirements 112

5.2 IPP Object Conformance Requirements 113

5.2.1 Objects 113

5.2.2 Operations 113

5.2.3 IPP Object Attributes 114

5.2.4 Extensions 114

5.2.5 Attribute Syntaxes 115

5.3 Charset and Natural Language Requirements 115

5.4 Security Conformance Requirements 115

6. IANA Considerations (registered and private extensions) 116

6.1 Typed 'keyword' and 'enum' Extensions 116

6.2 Attribute Extensibility 119

6.3 Attribute Syntax Extensibility 119

6.4 Operation Extensibility 120

6.5 Attribute Groups 120

6.6 Status Code Extensibility 120

6.7 Registration of MIME types/sub-types for document-formats 121

6.8 Registration of charsets for use in 'charset' attribute values121

7. Internationalization Considerations 121

8. Security Considerations 125

8.1 Security Scenarios 126

8.1.1 Client and Server in the Same Security Domain 126

8.1.2 Client and Server in Different Security Domains 126

8.1.3 Print by Reference 127

8.2 URIs for SSL3 and non-SSL3 Access 127

8.3 The "requesting-user-name" (name(MAX)) Operation Attribute 127

8.4 Restricted Queries 129

8.5 Queries on jobs submitted using non-IPP protocols 129

8.6 IPP Security Application Profile for SSL3 130

9. References 131

10. Authors' Addresses 134

11. Formats for IPP Registration Proposals 136

11.1 Type2 keyword attribute values registration 136

11.2 Type3 keyword attribute values registration 137

11.3 Type2 enum attribute values registration 137

11.4 Type3 enum attribute values registration 137

11.5 Attribute registration 138

11.6 Attribute Syntax registration 138

11.7 Operation registration 139

11.8 Attribute Group registration 139

11.9 Status code registration 139

12.APPENDIX A: Terminology 141

12.1 Conformance Terminology 141

12.1.1 NEED NOT 141

12.2 Model Terminology 141

12.2.1 Keyword 141

12.2.2 Attributes 141

12.2.2.1 Attribute Name 141

12.2.2.2 Attribute Group Name 142

12.2.2.3 Attribute Value 142

12.2.2.4 Attribute Syntax 142

12.2.3 Supports 142

12.2.4 print-stream page 144

12.2.5 impression 144

13.APPENDIX B: Status Codes and Suggested Status Code Messages 145

13.1 Status Codes 146

13.1.1 Informational 146

13.1.2 Successful Status Codes 146

13.1.2.1 successful-ok (0x0000) 146

13.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001) 146

13.1.2.3 successful-ok-conflicting-attributes (0x0002) 147

13.1.3 Redirection Status Codes 147

13.1.4 Client Error Status Codes 147

13.1.4.1 client-error-bad-request (0x0400) 147

13.1.4.2 client-error-forbidden (0x0401) 147

13.1.4.3 client-error-not-authenticated (0x0402) 148

13.1.4.4 client-error-not-authorized (0x0403) 148

13.1.4.5 client-error-not-possible (0x0404) 148

13.1.4.6 client-error-timeout (0x0405) 148

13.1.4.7 client-error-not-found (0x0406) 149

13.1.4.8 client-error-gone (0x0407) 149

13.1.4.9 client-error-request-entity-too-large (0x0408) 149

13.1.4.10client-error-request-value-too-long (0x0409) 150

13.1.4.11client-error-document-format-not-supported (0x040A) 150

13.1.4.12client-error-attributes-or-values-not-supported (0x040B) 150

13.1.4.13client-error-uri-scheme-not-supported (0x040C) 151

13.1.4.14client-error-charset-not-supported (0x040D) 151

13.1.4.15client-error-conflicting-attributes (0x040E) 151

13.1.5 Server Error Status Codes 151

13.1.5.1 server-error-internal-error (0x0500) 151

13.1.5.2 server-error-operation-not-supported (0x0501) 152

13.1.5.3 server-error-service-unavailable (0x0502) 152

13.1.5.4 server-error-version-not-supported (0x0503) 152

13.1.5.5 server-error-device-error (0x0504) 152

13.1.5.6 server-error-temporary-error (0x0505) 153

13.1.5.7 server-error-not-accepting-jobs (0x0506) 153

13.1.5.8 server-error-busy (0x0507) 153

13.1.5.9 server-error-job-canceled (0x0508) 153

13.2 Status Codes for IPP Operations 153

14.APPENDIX C: "media" keyword values 155

15.APPENDIX D: Processing IPP Attributes 160

15.1 Fidelity 160

15.2 Page Description Language (PDL) Override 161

15.3 Using Job Template Attributes During Document Processing. 163

16.APPENDIX E: Generic Directory Schema 166

17.APPENDIX F: Change History for the Model and Semantics document 168

18.FULL COPYRIGHT STATEMENT 173

1. Introduction

The Internet Printing Protocol (IPP) is an application level protocol

that can be used for distributed printing using Internet tools and

technologies. IPP version 1.0 (IPP/1.0) focuses only on end user

functionality. This document is just one of a suite of documents

that fully define IPP. The full set of IPP documents includes:

Design Goals for an Internet Printing Protocol [RFC2567]

Rationale for the Structure and Model and Protocol for the Internet

Printing Protocol [RFC2568]

Internet Printing Protocol/1.0: Model and Semantics (this document)

Internet Printing Protocol/1.0: Encoding and Transport [RFC2565]

Internet Printing Protocol/1.0: Implementer's Guide [ipp-iig]

Mapping between LPD and IPP Protocols [RFC2569]

Anyone reading these documents for the first time is strongly

encouraged to read the IPP documents in the above order.

This document is laid out as follows:

- The rest of Section 1 is an introduction to the IPP simplified

model for distributed printing.

- Section 2 introduces the object types covered in the model with

their basic behaviors, attributes, and interactions.

- Section 3 defines the operations included in IPP/1.0. IPP

operations are synchronous, therefore, for each operation, there

is a both request and a response.

- Section 4 defines the attributes (and their syntaxes) that are

used in the model.

- Sections 5 - 6 summarizes the implementation conformance

requirements for objects that support the protocol and IANA

considerations, respectively.

- Sections 7 - 11 cover the Internationalization and Security

considerations as well as References, Author contact information,

and Formats for Registration Proposals.

- Sections 12 - 14 are appendices that cover Terminology, Status

Codes and Messages, and "media" keyword values.

Note: This document uses terms such as "attributes",

"keywords", and "support". These terms have special

meaning and are defined in the model terminology section

12.2. Capitalized terms, such as MUST, MUST NOT, REQUIRED,

SHOULD, SHOULD NOT, MAY, NEED NOT, and OPTIONAL, have

special meaning relating to conformance. These terms are

defined in section 12.1 on conformance terminology, most of

which is taken from RFC2119 [RFC2119].

- Section 15 is an appendix that helps to clarify the effects of

interactions between related attributes and their values.

- Section 16 is an appendix that enumerates the subset of Printer

attributes that form a generic directory schema. These

attributes are useful when registering a Printer so that a

client can find the Printer not just by name, but by filtered

searches as well.

- Section 17 is an appendix that provides a Change History

summarizing the clarification and changes that might affect an

implementation since the June 30, 1998 draft.

1.1 Simplified Printing Model

In order to achieve its goal of realizing a workable printing

protocol for the Internet, the Internet Printing Protocol (IPP) is

based on a simplified printing model that abstracts the many

components of real world printing solutions. The Internet is a

distributed computing environment where requesters of print services

(clients, applications, printer drivers, etc.) cooperate and interact

with print service providers. This model and semantics document

describes a simple, abstract model for IPP even though the underlying

configurations may be complex "n-tier" client/server systems. An

important simplifying step in the IPP model is to expose only the key

objects and interfaces required for printing. The model described in

this model document does not include features, interfaces, and

relationships that are beyond the scope of the first version of IPP

(IPP/1.0). IPP/1.0 incorporates many of the relevant ideas and

lessons learned from other specification and development efforts

[HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS] [RFC1179] [SWP]. IPP is

heavily influenced by the printing model introduced in the Document

Printing Application (DPA) [ISO10175] standard. Although DPA

specifies both end user and administrative features, IPP version 1.0

(IPP/1.0) focuses only on end user functionality.

The IPP/1.0 model encapsulates the important components of

distributed printing into two object types:

- Printer (Section 2.1)

- Job (Section 2.2)

Each object type has an associated set of operations (see section 3)

and attributes (see section 4).

It is important, however, to understand that in real system

implementations (which lie underneath the abstracted IPP/1.0 model),

there are other components of a print service which are not

explicitly defined in the IPP/1.0 model. The following figure

illustrates where IPP/1.0 fits with respect to these other

components.

+--------------+

Application

o +. . . . . . .

\/ Spooler

/ \ +. . . . . . . +---------+

End-User Print Driver --- File

+-----------+ +-----+ +------+-------+ +----+----+

Browser GUI

+-----+-----+ +--+--+

+---+------------+---+

N D S IPP Client ------------+

O I E +---------+----------+

T R C

I E U

F C R -------------- Transport ------------------

I T I

C O T --+

A R Y +--------+--------+

T Y IPP Server

I +--------+--------+

O

N +-----------------+ IPP Printer

Print Service

+-----------------+

--+

+-----------------+

Output Device(s)

+-----------------+

An IPP Printer object encapsulates the functions normally associated

with physical output devices along with the spooling, scheduling and

multiple device management functions often associated with a print

server. Printer objects are optionally registered as entries in a

directory where end users find and select them based on some sort of

filtered and context based searching mechanism (see section 16). The

directory is used to store relatively static information about the

Printer, allowing end users to search for and find Printers that

match their search criteria, for example: name, context, printer

capabilities, etc. The more dynamic information, such as state,

currently loaded and ready media, number of jobs at the Printer,

errors, warnings, and so forth, is directly associated with the

Printer object itself rather than with the entry in the directory

which only represents the Printer object.

IPP clients implement the IPP protocol on the client side and give

end users (or programs running on behalf of end users) the ability to

query Printer objects and submit and manage print jobs. An IPP

server is just that part of the Printer object that implements the

server-side protocol. The rest of the Printer object implements (or

gateways into) the application semantics of the print service itself.

The Printer objects may be embedded in an output device or may be

implemented on a host on the network that communicates with an output

device.

When a job is submitted to the Printer object and the Printer object

validates the attributes in the submission request, the Printer

object creates a new Job object. The end user then interacts with

this new Job object to query its status and monitor the progress of

the job. End users may also cancel the print job by using the Job

object's Cancel-Job operation. The notification service is out of

scope for IPP/1.0, but using such a notification service, the end

user is able to register for and receive Printer specific and Job

specific events. An end user can query the status of Printer objects

and can follow the progress of Job objects by polling using the Get-

Printer-Attributes, Get-Jobs, and Get-Job-Attributes operations.

2. IPP Objects

The IPP/1.0 model introduces objects of type Printer and Job. Each

type of object models relevant aspects of a real-world entity such as

a real printer or real print job. Each object type is defined as a

set of possible attributes that may be supported by instances of that

object type. For each object (instance), the actual set of supported

attributes and values describe a specific implementation. The

object's attributes and values describe its state, capabilities,

realizable features, job processing functions, and default behaviors

and characteristics. For example, the Printer object type is defined

as a set of attributes that each Printer object potentially supports.

In the same manner, the Job object type is defined as a set of

attributes that are potentially supported by each Job object.

Each attribute included in the set of attributes defining an object

type is labeled as:

- "REQUIRED": each object MUST support the attribute.

- "OPTIONAL": each object MAY support the attribute.

There is no such similar labeling of attribute values. However, if

an implementation supports an attribute, it MUST support at least one

of the possible values for that attribute.

2.1 Printer Object

The major component of the IPP/1.0 model is the Printer object. A

Printer object implements the server-side of the IPP/1.0 protocol.

Using the protocol, end users may query the attributes of the Printer

object and submit print jobs to the Printer object. The actual

implementation components behind the Printer abstraction may take on

different forms and different configurations. However, the model

abstraction allows the details of the configuration of real

components to remain opaque to the end user. Section 3 describes

each of the Printer operations in detail.

The capabilities and state of a Printer object are described by its

attributes. Printer attributes are divided into two groups:

- "job-template" attributes: These attributes describe supported

job processing capabilities and defaults for the Printer object.

(See section 4.2)

- "printer-description" attributes: These attributes describe the

Printer object's identification, state, location, references to

other sources of information about the Printer object, etc. (see

section 4.4)

Since a Printer object is an abstraction of a generic document output

device and print service provider, a Printer object could be used to

represent any real or virtual device with semantics consistent with

the Printer object, such as a fax device, an imager, or even a CD

writer.

Some examples of configurations supporting a Printer object include:

1) An output device with no spooling capabilities

2) An output device with a built-in spooler

3) A print server supporting IPP with one or more associated output

devices

3a) The associated output devices may or may not be capable of

spooling jobs

3b) The associated output devices may or may not support IPP

The following figures show some examples of how Printer objects can

be realized on top of various distributed printing configurations.

The embedded case below represents configurations 1 and 2. The hosted

and fan-out figures below represent configurations 3a and 3b.

Legend:

##### indicates a Printer object which is

either embedded in an output device or is

hosted in a server. The Printer object

might or might not be capable of queuing/spooling.

any indicates any network protocol or direct

connect, including IPP

embedded printer:

output device

+---------------+

O +--------+ ###########

/\ client ------------IPP------------># Printer #

/ \ +--------+ # Object #

###########

+---------------+

hosted printer:

+---------------+

O +--------+ ###########

/\ client --IPP--># Printer #-any-> output device

/ \ +--------+ # Object #

########### +---------------+

+---------------+

fan out:

+--> output device

any/

O +--------+ ########### / +---------------+

/\ client -IPP-># Printer #--*

/ \ +--------+ # Object # \ +---------------+

########### any\

+--> output device

+---------------+

2.2 Job Object

A Job object is used to model a print job. A Job object contains

documents. The information required to create a Job object is sent

in a create request from the end user via an IPP Client to the

Printer object. The Printer object validates the create request, and

if the Printer object accepts the request, the Printer object creates

the new Job object. Section 3 describes each of the Job operations

in detail.

The characteristics and state of a Job object are described by its

attributes. Job attributes are grouped into two groups as follows:

- "job-template" attributes: These attributes can be supplied by

the client or end user and include job processing instructions

which are intended to override any Printer object defaults and/or

instructions embedded within the document data. (See section 4.2)

- "job-description" attributes: These attributes describe the Job

object's identification, state, size, etc. The client supplies

some of these attributes, and the Printer object generates others.

(See section 4.3)

An implementation MUST support at least one document per Job object.

An implementation MAY support multiple documents per Job object. A

document is either:

- a stream of document data in a format supported by the Printer

object (typically a Page Description Language - PDL), or

- a reference to such a stream of document data

In IPP/1.0, a document is not modeled as an IPP object, therefore it

has no object identifier or associated attributes. All job

processing instructions are modeled as Job object attributes. These

attributes are called Job Template attributes and they apply equally

to all documents within a Job object.

2.3 Object Relationships

IPP objects have relationships that are maintained persistently along

with the persistent storage of the object attributes.

A Printer object can represent either one or more physical output

devices or a logical device which "processes" jobs but never actually

uses a physical output device to put marks on paper. Examples of

logical devices include a Web page publisher or a gateway into an

online document archive or repository. A Printer object contains

zero or more Job objects.

A Job object is contained by exactly one Printer object, however the

identical document data associated with a Job object could be sent to

either the same or a different Printer object. In this case, a

second Job object would be created which would be almost identical to

the first Job object, however it would have new (different) Job

object identifiers (see section 2.4).

A Job object is either empty (before any documents have been added)

or contains one or more documents. If the contained document is a

stream of document data, that stream can be contained in only one

document. However, there can be identical copies of the stream in

other documents in the same or different Job objects. If the

contained document is just a reference to a stream of document data,

other documents (in the same or different Job object(s)) may contain

the same reference.

2.4 Object Identity

All Printer and Job objects are identified by a Uniform Resource

Identifier (URI) [RFC2396] so that they can be persistently and

unambiguously referenced. The notion of a URI is a useful concept,

however, until the notion of URI is more stable (i.e., defined more

completely and deployed more widely), it is expected that the URIs

used for IPP objects will actually be URLs [RFC2396]. Since every

URL is a specialized form of a URI, even though the more generic term

URI is used throughout the rest of this document, its usage is

intended to cover the more specific notion of URL as well.

An administrator configures Printer objects to either support or not

support authentication and/or message privacy using SSL3 [SSL] (the

mechanism for security configuration is outside the scope of

IPP/1.0). In some situations, both types of connections (both

authenticated and unauthenticated) can be established using a single

communication channel that has some sort of negotiation mechanism.

In other situations, multiple communication channels are used, one

for each type of security configuration. Section 8 provides a full

description of all security considerations and configurations.

If a Printer object supports more than one communication channel,

some or all of those channels might support and/or require different

security mechanisms. In such cases, an administrator could expose

the simultaneous support for these multiple communication channels as

multiple URIs for a single Printer object where each URI represents

one of the communication channels to the Printer object. To support

this flexibility, the IPP Printer object type defines a multi-valued

identification attribute called the "printer-uri-supported"

attribute. It MUST contain at least one URI. It MAY contain more

than one URI. That is, every Printer object will have at least one

URI that identifies at least one communication channel to the Printer

object, but it may have more than one URI where each URI identifies a

different communication channel to the Printer object. The

"printer-uri-supported" attribute has a companion attribute, the

"uri-security-supported" attribute, that has the same cardinality as

"printer-uri-supported". The purpose of the "uri-security-supported"

attribute is to indicate the security mechanisms (if any) used for

each URI listed in "printer-uri-supported". These two attributes are

fully described in sections 4.4.1 and 4.4.2.

When a job is submitted to the Printer object via a create request,

the client supplies only a single Printer object URI. The client

supplied Printer object URI MUST be one of the values in the

"printer-uri-supported" Printer attribute.

Note: IPP/1.0 does not specify how the client oBTains the client

supplied URI, but it is RECOMMENDED that a Printer object be

registered as an entry in a directory service. End-users and

programs can then interrogate the directory searching for Printers.

Section 16 defines a generic schema for Printer object entries in the

directory service and describes how the entry acts as a bridge to the

actual IPP Printer object. The entry in the directory that

represents the IPP Printer object includes the possibly many URIs for

that Printer object as values in one its attributes.

When a client submits a create request to the Printer object, the

Printer object validates the request and creates a new Job object.

The Printer object assigns the new Job object a URI which is stored

in the "job-uri" Job attribute. This URI is then used by clients as

the target for subsequent Job operations. The Printer object

generates a Job URI based on its configured security policy and the

URI used by the client in the create request.

For example, consider a Printer object that supports both a

communication channel secured by the use of SSL3 (using HTTP over

SSL3 with an "https" schemed URI) and another open communication

channel that is not secured with SSL3 (using a simple "http" schemed

URI). If a client were to submit a job using the secure URI, the

Printer object would assign the new Job object a secure URI as well.

If a client were to submit a job using the open-channel URI, the

Printer would assign the new Job object an open-channel URI.

In addition, the Printer object also populates the Job object's

"job-printer-uri" attribute. This is a reference back to the Printer

object that created the Job object. If a client only has access to a

Job object's "job-uri" identifier, the client can query the Job's

"job-printer-uri" attribute in order to determine which Printer

object created the Job object. If the Printer object supports more

than one URI, the Printer object picks the one URI supplied by the

client when creating the job to build the value for and to populate

the Job's "job-printer-uri" attribute.

Allowing Job objects to have URIs allows for flexibility and

scalability. For example, in some implementations, the Printer

object might create Jobs that are processed in the same local

environment as the Printer object itself. In this case, the Job URI

might just be a composition of the Printer's URI and some unique

component for the Job object, such as the unique 32-bit positive

integer mentioned later in this paragraph. In other implementations,

the Printer object might be a central clearing-house for validating

all Job object creation requests, but the Job object itself might be

created in some environment that is remote from the Printer object.

In this case, the Job object's URI may have no physical-location

relationship at all to the Printer object's URI. Again, the fact

that Job objects have URIs allows for flexibility and scalability,

however, many existing printing systems have local models or

interface constraints that force print jobs to be identified using

only a 32-bit positive integer rather than an independent URI. This

numeric Job ID is only unique within the context of the Printer

object to which the create request was originally submitted.

Therefore, in order to allow both types of client access to IPP Job

objects (either by Job URI or by numeric Job ID), when the Printer

object successfully processes a create request and creates a new Job

object, the Printer object MUST generate both a Job URI and a Job ID.

The Job ID (stored in the "job-id" attribute) only has meaning in the

context of the Printer object to which the create request was

originally submitted. This requirement to support both Job URIs and

Job IDs allows all types of clients to access Printer objects and Job

objects no matter the local constraints imposed on the client

implementation.

In addition to identifiers, Printer objects and Job objects have

names ("printer-name" and "job-name"). An object name NEED NOT be

unique across all instances of all objects. A Printer object's name

is chosen and set by an administrator through some mechanism outside

the scope of IPP/1.0. A Job object's name is optionally chosen and

supplied by the IPP client submitting the job. If the client does

not supply a Job object name, the Printer object generates a name for

the new Job object. In all cases, the name only has local meaning.

To summarize:

- Each Printer object is identified with one or more URIs. The

Printer's "printer-uri-supported" attribute contains the URI(s).

- The Printer object's "uri-security-supported" attribute

identifies the communication channel security protocols that may

or may not have been configured for the various Printer object

URIs (e.g., 'ssl3' or 'none').

- Each Job object is identified with a Job URI. The Job's "job-uri"

attribute contains the URI.

- Each Job object is also identified with Job ID which is a 32-bit,

positive integer. The Job's "job-id" attribute contains the Job

ID. The Job ID is only unique within the context of the Printer

object which created the Job object.

- Each Job object has a "job-printer-uri" attribute which contains

the URI of the Printer object that was used to create the Job

object. This attribute is used to determine the Printer object

that created a Job object when given only the URI for the Job

object. This linkage is necessary to determine the languages,

charsets, and operations which are supported on that Job (the

basis for such support comes from the creating Printer object).

- Each Printer object has a name (which is not necessarily unique).

The administrator chooses and sets this name through some

mechanism outside the scope of IPP/1.0 itself. The Printer

object's "printer-name" attribute contains the name.

- Each Job object has a name (which is not necessarily unique). The

client optionally supplies this name in the create request. If

the client does not supply this name, the Printer object generates

a name for the Job object. The Job object's "job-name" attribute

contains the name.

3. IPP Operations

IPP objects support operations. An operation consists of a request

and a response. When a client communicates with an IPP object, the

client issues an operation request to the URI for that object.

Operation requests and responses have parameters that identify the

operation. Operations also have attributes that affect the run-time

characteristics of the operation (the intended target, localization

information, etc.). These operation-specific attributes are called

operation attributes (as compared to object attributes such as

Printer object attributes or Job object attributes). Each request

carries along with it any operation attributes, object attributes,

and/or document data required to perform the operation. Each request

requires a response from the object. Each response indicates success

or failure of the operation with a status code as a response

parameter. The response contains any operation attributes, object

attributes, and/or status messages generated during the execution of

the operation request.

This section describes the semantics of the IPP operations, both

requests and responses, in terms of the parameters, attributes, and

other data associated with each operation.

The IPP/1.0 Printer operations are:

Print-Job (section 3.2.1)

Print-URI (section 3.2.2)

Validate-Job (section 3.2.3)

Create-Job (section 3.2.4)

Get-Printer-Attributes (section 3.2.5)

Get-Jobs (section 3.2.6)

The Job operations are:

Send-Document (section 3.3.1)

Send-URI (section 3.3.2)

Cancel-Job (section 3.3.3)

Get-Job-Attributes (section 3.3.4)

The Send-Document and Send-URI Job operations are used to add a new

document to an existing multi-document Job object created using the

Create-Job operation.

3.1 Common Semantics

All IPP operations require some common parameters and operation

attributes. These common elements and their semantic characteristics

are defined and described in more detail in the following sections.

3.1.1 Required Parameters

Every operation request contains the following REQUIRED parameters:

- a "version-number",

- an "operation-id",

- a "request-id", and

- the attributes that are REQUIRED for that type of request.

Every operation response contains the following REQUIRED parameters:

- a "version-number",

- a "status-code",

- the "request-id" that was supplied in the corresponding request,

and

- the attributes that are REQUIRED for that type of response.

The encoding and transport document [RFC2565] defines special rules

for the encoding of these parameters. All other operation elements

are represented using the more generic encoding rules for attributes

and groups of attributes.

3.1.2 Operation IDs and Request IDs

Each IPP operation request includes an identifying "operation-id"

value. Valid values are defined in the "operations-supported"

Printer attribute section (see section 4.4.13). The client specifies

which operation is being requested by supplying the correct

"operation-id" value.

In addition, every invocation of an operation is identified by a

"request-id" value. For each request, the client chooses the

"request-id" which MUST be an integer (possibly unique depending on

client requirements) in the range from 1 to 2**31 - 1 (inclusive).

This "request-id" allows clients to manage multiple outstanding

requests. The receiving IPP object copies all 32-bits of the client-

supplied "request-id" attribute into the response so that the client

can match the response with the correct outstanding request, even if

the "request-id" is out of range. If the request is terminated

before the complete "request-id" is received, the IPP object rejects

the request and returns a response with a "request-id" of 0.

Note: In some cases, the transport protocol underneath IPP might be a

connection oriented protocol that would make it impossible for a

client to receive responses in any order other than the order in

which the corresponding requests were sent. In such cases, the

"request-id" attribute would not be essential for correct protocol

operation. However, in other mappings, the operation responses can

come back in any order. In these cases, the "request-id" would be

essential.

3.1.3 Attributes

Operation requests and responses are both composed of groups of

attributes and/or document data. The attributes groups are:

- Operation Attributes: These attributes are passed in the

operation and affect the IPP object's behavior while processing

the operation request and may affect other attributes or groups

of attributes. Some operation attributes describe the document

data associated with the print job and are associated with new

Job objects, however most operation attributes do not persist

beyond the life of the operation. The description of each

operation attribute includes conformance statements indicating

which operation attributes are REQUIRED and which are OPTIONAL

for an IPP object to support and which attributes a client MUST

supply in a request and an IPP object MUST supply in a response.

- Job Template Attributes: These attributes affect the processing

of a job. A client OPTIONALLY supplies Job Template Attributes

in a create request, and the receiving object MUST be prepared to

receive all supported attributes. The Job object can later be

queried to find out what Job Template attributes were originally

requested in the create request, and such attributes are returned

in the response as Job Object Attributes. The Printer object can

be queried about its Job Template attributes to find out what

type of job processing capabilities are supported and/or what the

default job processing behaviors are, though such attributes are

returned in the response as Printer Object Attributes. The

"ipp-attribute-fidelity" operation attribute affects processing

of all client-supplied Job Template attributes (see section 15

for a full description of "ipp-attribute-fidelity" and its

relationship to other attributes).

- Job Object Attributes: These attributes are returned in response

to a query operation directed at a Job object.

- Printer Object Attributes: These attributes are returned in

response to a query operation directed at a Printer object.

- Unsupported Attributes: In a create request, the client supplies

a set of Operation and Job Template attributes. If any of these

attributes or their values is unsupported by the Printer object,

the Printer object returns the set of unsupported attributes in

the response. Section 15 gives a full description of how Job

Template attributes supplied by the client in a create request

are processed by the Printer object and how unsupported

attributes are returned to the client. Because of extensibility,

any IPP object might receive a request that contains new or

unknown attributes or values for which it has no support. In such

cases, the IPP object processes what it can and returns the

unsupported attributes in the response.

Later in this section, each operation is formally defined by

identifying the allowed and expected groups of attributes for each

request and response. The model identifies a specific order for each

group in each request or response, but the attributes within each

group may be in any order, unless specified otherwise.

Each attribute specification includes the attribute's name followed

by the name of its attribute syntax(es) in parenthesizes. In

addition, each 'integer' attribute is followed by the allowed range

in parentheses, (m:n), for values of that attribute. Each 'text' or

'name' attribute is followed by the maximum size in octets in

parentheses, (size), for values of that attribute. For more details

on attribute syntax notation, see the descriptions of these

attributes syntaxes in section 4.1.

Note: Document data included in the operation is not strictly an

attribute, but it is treated as a special attribute group for

ordering purposes. The only operations that support supplying the

document data within an operation request are Print-Job and Send-

Document. There are no operation responses that include document

data.

Note: Some operations are REQUIRED for IPP objects to support; the

others are OPTIONAL (see section 5.2.2). Therefore, before using an

OPTIONAL operation, a client SHOULD first use the REQUIRED Get-

Printer-Attributes operation to query the Printer's "operations-

supported" attribute in order to determine which OPTIONAL Printer and

Job operations are actually supported. The client SHOULD NOT use an

OPTIONAL operation that is not supported. When an IPP object

receives a request to perform an operation it does not support, it

returns the 'server-error-operation-not-supported' status code (see

section 13.1.5.2). An IPP object is non-conformant if it does not

support a REQUIRED operation.

3.1.4 Character Set and Natural Language Operation Attributes

Some Job and Printer attributes have values that are text strings and

names intended for human understanding rather than machine

understanding (see the 'text' and 'name' attribute syntax

descriptions in section 4.1). The following sections describe two

special Operation Attributes called "attributes-charset" and

"attributes-natural-language". These attributes are always part of

the Operation Attributes group. For most attribute groups, the order

of the attributes within the group is not important. However, for

these two attributes within the Operation Attributes group, the order

is critical. The "attributes-charset" attribute MUST be the first

attribute in the group and the "attributes-natural-language"

attribute MUST be the second attribute in the group. In other words,

these attributes MUST be supplied in every IPP request and response,

they MUST come first in the group, and MUST come in the specified

order. For job creation operations, the IPP Printer implementation

saves these two attributes with the new Job object as Job Description

attributes. For the sake of brevity in this document, these

operation attribute descriptions are not repeated with every

operation request and response, but have a reference back to this

section instead.

3.1.4.1 Request Operation Attributes

The client MUST supply and the Printer object MUST support the

following REQUIRED operation attributes in every IPP/1.0 operation

request:

"attributes-charset" (charset):

This operation attribute identifies the charset (coded character

set and encoding method) used by any 'text' and 'name'

attributes that the client is supplying in this request. It

also identifies the charset that the Printer object MUST use (if

supported) for all 'text' and 'name' attributes and status

messages that the Printer object returns in the response to this

request. See Sections 4.1.1 and 4.1.2 for the specification of

the 'text' and 'name' attribute syntaxes.

All clients and IPP objects MUST support the 'utf-8' charset

[RFC2279] and MAY support additional charsets provided that they

are registered with IANA [IANA-CS]. If the Printer object does

not support the client supplied charset value, the Printer

object MUST reject the request, set the "attributes-charset" to

'utf-8' in the response, and return the 'client-error-charset-

not-supported' status code and any 'text' or 'name' attributes

using the 'utf-8' charset. The Printer object MUST indicate the

charset(s) supported as the values of the "charset-supported"

Printer attribute (see Section 4.4.15), so that the client can

query to determine which charset(s) are supported.

Note to client implementers: Since IPP objects are only required

to support the 'utf-8' charset, in order to maximize

interoperability with multiple IPP object implementations, a

client may want to supply 'utf-8' in the "attributes-charset"

operation attribute, even though the client is only passing and

able to present a simpler charset, such as US-ASCII or ISO-

8859-1. Then the client will have to filter out (or charset

convert) those characters that are returned in the response that

it cannot present to its user. On the other hand, if both the

client and the IPP objects also support a charset in common

besides utf-8, the client may want to use that charset in order

to avoid charset conversion or data loss.

See the 'charset' attribute syntax description in Section 4.1.7

for the syntax and semantic interpretation of the values of this

attribute and for example values.

"attributes-natural-language" (naturalLanguage):

This operation attribute identifies the natural language used by

any 'text' and 'name' attributes that the client is supplying in

this request. This attribute also identifies the natural

language that the Printer object SHOULD use for all 'text' and '

name' attributes and status messages that the Printer object

returns in the response to this request.

There are no REQUIRED natural languages required for the Printer

object to support. However, the Printer object's "generated-

natural-language-supported" attribute identifies the natural

languages supported by the Printer object and any contained Job

objects for all text strings generated by the IPP object. A

client MAY query this attribute to determine which natural

language(s) are supported for generated messages.

For any of the attributes for which the Printer object generates

text, i.e., for the "job-state-message", "printer-state-

message", and status messages (see Section 3.1.6), the Printer

object MUST be able to generate these text strings in any of its

supported natural languages. If the client requests a natural

language that is not supported, the Printer object MUST return

these generated messages in the Printer's configured natural

language as specified by the Printer's "natural-language-

configured" attribute" (see Section 4.4.16).

For other 'text' and 'name' attributes supplied by the client,

authentication system, operator, system administrator, or

manufacturer (i.e., for "job-originating-user-name", "printer-

name" (name), "printer-location" (text), "printer-info" (text),

and "printer-make-and-model" (text)), the Printer object is only

required to support the configured natural language of the

Printer identified by the Printer object's "natural-language-

configured" attribute, though support of additional natural

languages for these attributes is permitted.

For any 'text' or 'name' attribute in the request that is in a

different natural language than the value supplied in the

"attributes-natural-language" operation attribute, the client

MUST use the Natural Language Override mechanism (see sections

4.1.1.2 and 4.1.2.2) for each such attribute value supplied.

The client MAY use the Natural Language Override mechanism

redundantly, i.e., use it even when the value is in the same

natural language as the value supplied in the "attributes-

natural-language" operation attribute of the request.

The IPP object MUST accept any natural language and any Natural

Language Override, whether the IPP object supports that natural

language or not (and independent of the value of the "ipp-

attribute-fidelity" Operation attribute). That is the IPP

object accepts all client supplied values no matter what the

values are in the Printer object's "generated-natural-language-

supported" attribute. That attribute, "generated-natural-

language-supported", only applies to generated messages,

not client supplied messages. The IPP object MUST remember that

natural language for all client-supplied attributes, and when

returning those attributes in response to a query, the IPP

object MUST indicate that natural language.

Each value whose attribute syntax type is 'text' or 'name' (see

sections 4.1.1 and 4.1.2) has an Associated Natural-Language.

This document does not specify how this association is stored in

a Printer or Job object. When such a value is encoded in a

request or response, the natural language is either implicit or

explicit:

- In the implicit case, the value contains only the

text/name value, and the language is specified by the

"attributes-natural-language" operation attribute in the

request or response (see sections 4.1.1.1

textWithoutLanguage and 4.1.2.1 nameWithoutLanguage).

- In the explicit case (also known as the Natural-Language

Override case), the value contains both the language and

the text/name value (see sections 4.1.1.2

textWithLanguage and 4.1.2.2 nameWithLanguage).

For example, the "job-name" attribute MAY be supplied by the

client in a create request. The text value for this attribute

will be in the natural language identified by the "attribute-

natural-language" attribute, or if different, as identified by

the Natural Language Override mechanism. If supplied, the IPP

object will use the value of the "job-name" attribute to

populate the Job object's "job-name" attribute. Whenever any

client queries the Job object's "job-name" attribute, the IPP

object returns the attribute as stored and uses the Natural

Language Override mechanism to specify the natural language, if

it is different from that reported in the "attributes-natural-

language" operation attribute of the response. The IPP object

MAY use the Natural Language Override mechanism redundantly,

i.e., use it even when the value is in the same natural language

as the value supplied in the "attributes-natural-language"

operation attribute of the response.

An IPP object MUST NOT reject a request based on a supplied

natural language in an "attributes-natural-language" Operation

attribute or in any attribute that uses the Natural Language

Override.

See the 'naturalLanguage' attribute syntax description in

section 4.1.8 for the syntax and semantic interpretation of the

values of this attribute and for example values.

Clients SHOULD NOT supply 'text' or 'name' attributes that use an

illegal combination of natural language and charset. For example,

suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and

'iso-8859-7'. Suppose also, that it supports natural languages 'en'

(English), 'fr' (French), and 'el' (Greek). Although the Printer

object supports the charset 'iso-8859-1' and natural language 'el',

it probably does not support the combination of Greek text strings

using the 'iso-8859-1' charset. The Printer object handles this

apparent incompatibility differently depending on the context in

which it occurs:

- In a create request: If the client supplies a text or name

attribute (for example, the "job-name" operation attribute) that

uses an apparently incompatible combination, it is a client

choice that does not affect the Printer object or its correct

operation. Therefore, the Printer object simply accepts the

client supplied value, stores it with the Job object, and

responds back with the same combination whenever the client (or

any client) queries for that attribute.

- In a query-type operation, like Get-Printer-Attributes: If the

client requests an apparently incompatible combination, the

Printer object responds (as described in section 3.1.4.2) using

the Printer's configured natural language rather than the natural

language requested by the client.

In either case, the Printer object does not reject the request

because of the apparent incompatibility. The potential incompatible

combination of charset and natural language can occur either at the

global operation level or at the Natural Language Override

attribute-by-attribute level. In addition, since the response always

includes explicit charset and natural language information, there is

never any question or ambiguity in how the client interprets the

response.

3.1.4.2 Response Operation Attributes

The Printer object MUST supply and the client MUST support the

following REQUIRED operation attributes in every IPP/1.0 operation

response:

"attributes-charset" (charset):

This operation attribute identifies the charset used by any '

text' and 'name' attributes that the Printer object is returning

in this response. The value in this response MUST be the same

value as the "attributes-charset" operation attribute supplied

by the client in the request. If this is not possible

(i.e., the charset requested is not supported), the request

would have been rejected. See "attributes-charset" described in

Section 3.1.4.1 above.

If the Printer object supports more than just the 'utf-8'

charset, the Printer object MUST be able to code convert between

each of the charsets supported on a highest fidelity possible

basis in order to return the 'text' and 'name' attributes in the

charset requested by the client. However, some information loss

MAY occur during the charset conversion depending on the

charsets involved. For example, the Printer object may convert

from a UTF-8 'a' to a US-ASCII 'a' (with no loss of

information), from an ISO Latin 1 CAPITAL LETTER A WITH ACUTE

ACCENT to US-ASCII 'A' (losing the accent), or from a UTF-8

Japanese Kanji character to some ISO Latin 1 error character

indication such as '?', decimal code equivalent, or to the

absence of a character, depending on implementation.

Note: Whether an implementation that supports more than one

charset stores the data in the charset supplied by the client or

code converts to one of the other supported charsets, depends on

implementation. The strategy should try to minimize loss of

information during code conversion. On each response, such an

implementation converts from its internal charset to that

requested.

"attributes-natural-language" (naturalLanguage):

This operation attribute identifies the natural language used by

any 'text' and 'name' attributes that the IPP object is

returning in this response. Unlike the "attributes-charset"

operation attribute, the IPP object NEED NOT return the same

value as that supplied by the client in the request. The IPP

object MAY return the natural language of the Job object or the

Printer's configured natural language as identified by the

Printer object's "natural-language-configured" attribute, rather

than the natural language supplied by the client. For any '

text' or 'name' attribute or status message in the response that

is in a different natural language than the value returned in

the "attributes-natural-language" operation attribute, the IPP

object MUST use the Natural Language Override mechanism (see

sections 4.1.1.2 and 4.1.2.2) on each attribute value returned.

The IPP object MAY use the Natural Language Override mechanism

redundantly, i.e., use it even when the value is in the same

natural language as the value supplied in the "attributes-

natural-language" operation attribute of the response.

3.1.5 Operation Targets

All IPP operations are directed at IPP objects. For Printer

operations, the operation is always directed at a Printer object

using one of its URIs (i.e., one of the values in the Printer

object's "printer-uri-supported" attribute). Even if the Printer

object supports more than one URI, the client supplies only one URI

as the target of the operation. The client identifies the target

object by supplying the correct URI in the "printer-uri (uri)"

operation attribute.

For Job operations, the operation is directed at either:

- The Job object itself using the Job object's URI. In this case,

the client identifies the target object by supplying the correct

URI in the "job-uri (uri)" operation attribute.

- The Printer object that created the Job object using both the

Printer objects URI and the Job object's Job ID. Since the

Printer object that created the Job object generated the Job ID,

it MUST be able to correctly associate the client supplied Job ID

with the correct Job object. The client supplies the Printer

object's URI in the "printer-uri (uri)" operation attribute and

the Job object's Job ID in the "job-id (integer(1:MAX))"

operation attribute.

If the operation is directed at the Job object directly using the Job

object's URI, the client MUST NOT include the redundant "job-id"

operation attribute.

The operation target attributes are REQUIRED operation attributes

that MUST be included in every operation request. Like the charset

and natural language attributes (see section 3.1.4), the operation

target attributes are specially ordered operation attributes. In all

cases, the operation target attributes immediately follow the

"attributes-charset" and "attributes-natural-language" attributes

within the operation attribute group, however the specific ordering

rules are:

- In the case where there is only one operation target attribute

(i.e., either only the "printer-uri" attribute or only the "job-

uri" attribute), that attribute MUST be the third attribute in

the operation attributes group.

- In the case where Job operations use two operation target

attributes (i.e., the "printer-uri" and "job-id" attributes), the

"printer-uri" attribute MUST be the third attribute and the

"job-id" attribute MUST be the fourth attribute.

In all cases, the target URIs contained within the body of IPP

operation requests and responses must be in absolute format rather

than relative format (a relative URL identifies a resource with the

scope of the HTTP server, but does not include scheme, host or port).

The following rules apply to the use of port numbers in URIs that

identify IPP objects:

1. If the URI scheme allows the port number to be explicitly

included in the URI string, and a port number is specified

within the URI, then that port number MUST be used by the client

to contact the IPP object.

2. If the URI scheme allows the port number to be explicitly

included in the URI string, and a port number is not specified

within the URI, then default port number implied by that URI

scheme MUST be used by the client to contact the IPP object.

3. If the URI scheme does not allow an explicit port number to be

specified within the URI, then the default port number implied

by that URI MUST be used by the client to contact the IPP

object.

Note: The IPP encoding and transport document [RFC2565] shows a

mapping of IPP onto HTTP/1.1 and defines a new default port number

for using IPP over HTTP/1.1.

3.1.6 Operation Status Codes and Messages

Every operation response includes a REQUIRED "status-code" parameter

and an OPTIONAL "status-message" operation attribute. The "status-

code" provides information on the processing of a request. A

"status-message" attribute provides a short textual description of

the status of the operation. The status code is intended for use by

automata, and the status message is intended for the human end user.

If a response does include a "status-message" attribute, an IPP

client NEED NOT examine or display the message, however it SHOULD do

so in some implementation specific manner.

The "status-code" value is a numeric value that has semantic meaning.

The "status-code" syntax is similar to a "type2 enum" (see section

4.1 on "Attribute Syntaxes") except that values can range only from

0x0000 to 0x7FFF. Section 13 describes the status codes, assigns the

numeric values, and suggests a corresponding status message for each

status code. The "status-message" attribute's syntax is "text(255)".

A client implementation of IPP SHOULD convert status code values into

any localized message that has semantic meaning to the end user.

If the Printer object supports the "status-message" operation

attribute, the Printer object MUST be able to generate this message

in any of the natural languages identified by the Printer object's

"generated-natural-language-supported" attribute (see the

"attributes-natural-language" operation attribute specified in

section 3.1.4.1). As described in section 3.1.4.1 for any returned '

text' attribute, if there is a choice for generating this message,

the Printer object uses the natural language indicated by the value

of the "attributes-natural-language" in the client request if

supported, otherwise the Printer object uses the value in the Printer

object's own "natural-language-configured" attribute. If the Printer

object supports the "status-message" operation attribute, it SHOULD

use the REQUIRED 'utf-8' charset to return a status message for the

following error status codes (see section 13): 'client-error-bad-

request', 'client-error-charset-not-supported', 'server-error-

internal-error', 'server-error-operation-not-supported', and '

server-error-version-not-supported'. In this case, it MUST set the

value of the "attributes-charset" operation attribute to 'utf-8' in

the error response.

3.1.7 Versions

Each operation request and response carries with it a "version-

number" parameter. Each value of the "version-number" is in the form

"X.Y" where X is the major version number and Y is the minor version

number. By including a version number in the client request, it

allows the client to identify which version of IPP it is interested

in using. If the IPP object does not support that version, the

object responds with a status code of 'server-error-version-not-

supported' along with the closest version number that is supported

(see section 13.1.5.4).

There is no version negotiation per se. However, if after receiving

a 'server-error-version-not-supported' status code from an IPP

object, there is nothing that prevents a client from trying again

with a different version number. In order to conform to IPP/1.0, an

implementation MUST support at least version '1.0'.

There is only one notion of "version number" that covers both IPP

Model and IPP Protocol changes. Thus the version number MUST change

when introducing a new version of the Model and Semantics document

[RFC2566] or a new version of the Encoding and Transport document

[RFC2565].

Changes to the major version number indicate structural or syntactic

changes that make it impossible for older version of IPP clients and

Printer objects to correctly parse and process the new or changed

attributes, operations and responses. If the major version number

changes, the minor version numbers is set to zero. As an example,

adding the "ipp-attribute-fidelity" attribute (if it had not been

part of version '1.0'), would have required a change to the major

version number. Items that might affect the changing of the major

version number include any changes to the Model and Semantics

document [RFC2566] or the Encoding and Transport [RFC2565] itself,

such as:

- reordering of ordered attributes or attribute sets

- changes to the syntax of existing attributes

- changing Operation or Job Template attributes from OPTIONAL to

REQUIRED and vice versa

- adding REQUIRED (for an IPP object to support) operation

attributes

- adding REQUIRED (for an IPP object to support) operation

attribute groups

- adding values to existing operation attributes

- adding REQUIRED operations

Changes to the minor version number indicate the addition of new

features, attributes and attribute values that may not be understood

by all IPP objects, but which can be ignored if not understood.

Items that might affect the changing of the minor version number

include any changes to the model objects and attributes but not the

encoding and transport rules [RFC2565] (except adding attribute

syntaxes). Examples of such changes are:

- grouping all extensions not included in a previous version into

a new version

- adding new attribute values

- adding new object attributes

- adding OPTIONAL (for an IPP object to support) operation

attributes (i.e., those attributes that an IPP object can ignore

without confusing clients)

- adding OPTIONAL (for an IPP object to support) operation

attribute groups (i.e., those attributes that an IPP object can

ignore without confusing clients)

- adding new attribute syntaxes

- adding OPTIONAL operations

- changing Job Description attributes or Printer Description

attributes from OPTIONAL to REQUIRED or vice versa.

The encoding of the "operation-id", the "version-number", the

"status-code", and the "request-id" MUST NOT change over any version

number (either major or minor). This rule guarantees that all future

versions will be backwards compatible with all previous versions (at

least for checking the "operation-id", the "version-number", and the

"request-id"). In addition, any protocol elements (attributes, error

codes, tags, etc.) that are not carried forward from one version to

the next are deprecated so that they can never be reused with new

semantics.

Implementations that support a certain major version NEED NOT support

ALL previous versions. As each new major version is defined (through

the release of a new specification), that major version will specify

which previous major versions MUST be supported in compliant

implementations.

3.1.8 Job Creation Operations

In order to "submit a print job" and create a new Job object, a

client issues a create request. A create request is any one of

following three operation requests:

- The Print-Job Request: A client that wants to submit a print job

with only a single document uses the Print-Job operation. The

operation allows for the client to "push" the document data to

the Printer object by including the document data in the request

itself.

- The Print-URI Request: A client that wants to submit a print job

with only a single document (where the Printer object "pulls" the

document data instead of the client "pushing" the data to the

Printer object) uses the Print-URI operation. In this case, the

client includes in the request only a URI reference to the

document data (not the document data itself).

- The Create-Job Request: A client that wants to submit a print job

with multiple documents uses the Create-Job operation. This

operation is followed by an arbitrary number of Send-Document

and/or Send-URI operations (each creating another document for

the newly create Job object). The Send-Document operation

includes the document data in the request (the client "pushes"

the document data to the printer), and the Send-URI operation

includes only a URI reference to the document data in the request

(the Printer "pulls" the document data from the referenced

location). The last Send-Document or Send-URI request for a

given Job object includes a "last-document" operation attribute

set to 'true' indicating that this is the last request.

Throughout this model specification, the term "create request" is

used to refer to any of these three operation requests.

A Create-Job operation followed by only one Send-Document operation

is semantically equivalent to a Print-Job operation, however, for

performance reasons, the client SHOULD use the Print-Job operation

for all single document jobs. Also, Print-Job is a REQUIRED

operation (all implementations MUST support it) whereas Create-Job is

an OPTIONAL operation, hence some implementations might not support

it.

Job submission time is the point in time when a client issues a

create request. The initial state of every Job object is the '

pending' or 'pending-held' state. Later, the Printer object begins

processing the print job. At this point in time, the Job object's

state moves to 'processing'. This is known as job processing time.

There are validation checks that must be done at job submission time

and others that must be performed at job processing time.

At job submission time and at the time a Validate-Job operation is

received, the Printer MUST do the following:

1. Process the client supplied attributes and either accept or

reject the request

2. Validate the syntax of and support for the scheme of any client

supplied URI

At job submission time the Printer object MUST validate whether or

not the supplied attributes, attribute syntaxes, and values are

supported by matching them with the Printer object's corresponding

"xxx-supported" attributes. See section 3.2.1.2 for details. [ipp-

iig] presents suggested steps for an IPP object to either accept or

reject any request and additional steps for processing create

requests.

At job submission time the Printer object NEED NOT perform the

validation checks reserved for job processing time such as:

1. Validating the document data

2. Validating the actual contents of any client supplied URI

(resolve the reference and follow the link to the document data)

At job submission time, these additional job processing time

validation checks are essentially useless, since they require

actually parsing and interpreting the document data, are not

guaranteed to be 100% accurate, and MUST be done, yet again, at job

processing time. Also, in the case of a URI, checking for

availability at job submission time does not guarantee availability

at job processing time. In addition, at job processing time, the

Printer object might discover any of the following conditions that

were not detectable at job submission time:

- runtime errors in the document data,

- nested document data that is in an unsupported format,

- the URI reference is no longer valid (i.e., the server hosting

the document might be down), or

- any other job processing error

At job processing time, since the Printer object has already

responded with a successful status code in the response to the create

request, if the Printer object detects an error, the Printer object

is unable to inform the end user of the error with an operation

status code. In this case, the Printer, depending on the error, can

set the "job-state", "job-state-reasons", or "job-state-message"

attributes to the appropriate value(s) so that later queries can

report the correct job status.

Note: Asynchronous notification of events is outside the scope of

IPP/1.0.

3.2 Printer Operations

All Printer operations are directed at Printer objects. A client

MUST always supply the "printer-uri" operation attribute in order to

identify the correct target of the operation.

3.2.1 Print-Job Operation

This REQUIRED operation allows a client to submit a print job with

only one document and supply the document data (rather than just a

reference to the data). See Section 15 for the suggested steps for

processing create operations and their Operation and Job Template

attributes.

3.2.1.1 Print-Job Request

The following groups of attributes are supplied as part of the

Print-Job Request:

Group 1: Operation Attributes

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.1. The Printer object

MUST copy these values to the corresponding Job Description

attributes described in sections 4.3.23 and 4.3.24.

Target:

The "printer-uri" (uri) operation attribute which is the target

for this operation as described in section 3.1.5.

Requesting User Name:

The "requesting-user-name" (name(MAX)) attribute SHOULD be

supplied by the client as described in section 8.3.

"job-name" (name(MAX)):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It contains the client

supplied Job name. If this attribute is supplied by the client,

its value is used for the "job-name" attribute of the newly

created Job object. The client MAY automatically include any

information that will help the end-user distinguish amongst

his/her jobs, such as the name of the application program along

with information from the document, such as the document name,

document subject, or source file name. If this attribute is not

supplied by the client, the Printer generates a name to use in

the "job-name" attribute of the newly created Job object (see

Section 4.3.5).

"ipp-attribute-fidelity" (boolean):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. The value 'true' indicates

that total fidelity to client supplied Job Template attributes

and values is required, else the Printer object MUST reject the

Print-Job request. The value 'false' indicates that a

reasonable attempt to print the Job object is acceptable and the

Printer object MUST accept the Print-job request. If not

supplied, the Printer object assumes the value is 'false'. All

Printer objects MUST support both types of job processing. See

section 15 for a full description of "ipp-attribute-fidelity"

and its relationship to other attributes, especially the Printer

object's "pdl-override-supported" attribute.

"document-name" (name(MAX)):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It contains the client

supplied document name. The document name MAY be different than

the Job name. Typically, the client software automatically

supplies the document name on behalf of the end user by using a

file name or an application generated name. If this attribute

is supplied, its value can be used in a manner defined by each

implementation. Examples include: printed along with the Job

(job start sheet, page adornments, etc.), used by accounting or

resource tracking management tools, or even stored along with

the document as a document level attribute. IPP/1.0 does not

support the concept of document level attributes.

"document-format" (mimeMediaType) :

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. The value of this attribute

identifies the format of the supplied document data. If the

client does not supply this attribute, the Printer object

assumes that the document data is in the format defined by the

Printer object's "document-format-default" attribute. If the

client supplies this attribute, but the value is not supported

by the Printer object, i.e., the value is not one of the values

of the Printer object's "document-format-supported" attribute,

the Printer object MUST reject the request and return the '

client-error-document-format-not-supported' status code.

"document-natural-language" (naturalLanguage):

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute. This attribute

specifies the natural language of the document for those

document-formats that require a specification of the natural

language in order to image the document unambiguously. There are

no particular values required for the Printer object to support.

"compression" (type3 keyword)

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute and the "compression-

supported" attribute (see section 4.4.29). The client supplied

"compression" operation attribute identifies the compression

algorithm used on the document data. If the client omits this

attribute, the Printer object MUST assume that the data is not

compressed. If the client supplies the attribute and the

Printer object supports the attribute, the Printer object uses

the corresponding decompression algorithm on the document data.

If the client supplies this attribute, but the value is not

supported by the Printer object, i.e., the value is not one of

the values of the Printer object's "compression-supported"

attribute, the Printer object MUST copy the attribute and its

value to the Unsupported Attributes response group, reject the

request, and return the 'client-error-attributes-or-values-not-

supported' status code.

"job-k-octets" (integer(0:MAX))

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute and the "job-k-

octets-supported" attribute (see section 4.4.30). The client

supplied "job-k-octets" operation attribute identifies the total

size of the document(s) in K octets being submitted (see section

4.3.17 for the complete semantics). If the client supplies the

attribute and the Printer object supports the attribute, the

value of the attribute is used to populate the Job object's

"job-k-octets" Job Description attribute.

Note: For this attribute and the following two attributes

("job-impressions", and "job-media-sheets"), if the client

supplies the attribute, but the Printer object does not support

the attribute, the Printer object ignores the client-supplied

value. If the client supplies the attribute and the Printer

supports the attribute, and the value is within the range of the

corresponding Printer object's "xxx-supported" attribute, the

Printer object MUST use the value to populate the Job object's

"xxx" attribute. If the client supplies the attribute and the

Printer supports the attribute, but the value is outside the

range of the corresponding Printer object's "xxx-supported"

attribute, the Printer object MUST copy the attribute and its

value to the Unsupported Attributes response group, reject the

request, and return the 'client-error-attributes-or-values-not-

supported' status code. If the client does not supply the

attribute, the Printer object MAY choose to populate the

corresponding Job object attribute depending on whether the

Printer object supports the attribute and is able to calculate

or discern the correct value.

"job-impressions" (integer(0:MAX))

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute and the "job-

impressions-supported" attribute (see section 4.4.31). The

client supplied "job-impressions" operation attribute identifies

the total size in number of impressions of the document(s) being

submitted (see section 4.3.18 for the complete semantics).

See note under "job-k-octets".

"job-media-sheets" (integer(0:MAX))

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute and the "job-media-

sheets-supported" attribute (see section 4.4.32). The client

supplied "job-media-sheets" operation attribute identifies the

total number of media sheets to be produced for this job (see

section 4.3.19 for the complete semantics).

See note under "job-k-octets".

Group 2: Job Template Attributes

The client OPTIONALLY supplies a set of Job Template attributes

as defined in section 4.2. If the client is not supplying any

Job Template attributes in the request, the client SHOULD omit

Group 2 rather than sending an empty group. However, a Printer

object MUST be able to accept an empty group.

Group 3: Document Content

The client MUST supply the document data to be processed.

Note: In addition to the MANDATORY parameters required for every

operation request, the simplest Print-Job Request consists of just

the "attributes-charset" and "attributes-natural-language" operation

attributes; the "printer-uri" target operation attribute; the

Document Content and nothing else. In this simple case, the Printer

object:

- creates a new Job object (the Job object contains a single

document),

- stores a generated Job name in the "job-name" attribute in the

natural language and charset requested (see Section 3.1.4.1) (if

those are supported, otherwise using the Printer object's default

natural language and charset), and

- at job processing time, uses its corresponding default value

attributes for the supported Job Template attributes that were

not supplied by the client as IPP attribute or embedded

instructions in the document data.

3.2.1.2 Print-Job Response

The Printer object MUST return to the client the following sets

of attributes as part of the Print-Job Response:

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in sections 14 and

3.1.6. If the client supplies unsupported or conflicting Job

Template attributes or values, the Printer object MUST reject or

accept the Print-Job request depending on the whether the client

supplied a 'true' or 'false' value for the "ipp-attribute-

fidelity" operation attribute. See the Implementer's Guide

[ipp-iig] for a complete description of the suggested steps for

processing a create request.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2.

Group 2: Unsupported Attributes

This is a set of Operation and Job Template attributes supplied

by the client (in the request) that are not supported by the

Printer object or that conflict with one another (see the

Implementer's Guide [ipp-iig]). If the Printer object is not

returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Unsupported attributes fall into three categories:

1. The Printer object does not support the supplied attribute

(no matter what the attribute syntax or value).

2. The Printer object does support the attribute, but does not

support some or all of the particular attribute syntaxes or

values supplied by the client (i.e., the Printer object does

not have those attribute syntaxes or values in its

corresponding "xxx-supported" attribute).

3. The Printer object does support the attributes and values

supplied, but the particular values are in conflict with one

another, because they violate a constraint, such as not being

able to staple transparencies.

In the case of an unsupported attribute name, the Printer object

returns the client-supplied attribute with a substituted "out-

of-band" value of 'unsupported' indicating no support for the

attribute itself (see the beginning of section 4.1).

In the case of a supported attribute with one or more

unsupported attribute syntaxes or values, the Printer object

simply returns the client-supplied attribute with the

unsupported attribute syntaxes or values as supplied by the

client. This indicates support for the attribute, but no

support for that particular attribute syntax or value. If the

client supplies a multi-valued attribute with more than one

value and the Printer object supports the attribute but only

supports a subset of the client-supplied attribute syntaxes or

values, the Printer object MUST return only those attribute

syntaxes or values that are unsupported.

In the case of two (or more) supported attribute values that are

in conflict with one another (although each is supported

independently, the values conflict when requested together

within the same job), the Printer object MUST return all the

values that it ignores or substitutes to resolve the conflict,

but not any of the values that it is still using. The choice

for exactly how to resolve the conflict is implementation

dependent. See The Implementer's Guide [ipp-iig] for an

example.

In these three cases, the value of the "ipp-attribute-fidelity"

supplied by the client does not affect what the Printer object

returns. The value of "ipp-attribute-fidelity" only affects

whether the Print-Job operation is accepted or rejected. If the

job is accepted, the client may query the job using the Get-

Job-Attributes operation requesting the unsupported attributes

that were returned in the create response to see which

attributes were ignored (not stored on the Job object) and which

attributes were stored with other (substituted) values.

Group 3: Job Object Attributes

"job-uri" (uri):

The Printer object MUST return the Job object's URI by returning

the contents of the REQUIRED "job-uri" Job object attribute.

The client uses the Job object's URI when directing operations

at the Job object. The Printer object always uses its

configured security policy when creating the new URI. However,

if the Printer object supports more than one URI, the Printer

object also uses information about which URI was used in the

Print-Job Request to generated the new URI so that the new URI

references the correct access channel. In other words, if the

Print-Job Request comes in over a secure channel, the Printer

object MUST generate a Job URI that uses the secure channel as

well.

"job-id" (integer(1:MAX)):

The Printer object MUST return the Job object's Job ID by

returning the REQUIRED "job-id" Job object attribute. The

client uses this "job-id" attribute in conjunction with the

"printer-uri" attribute used in the Print-Job Request when

directing Job operations at the Printer object.

"job-state":

The Printer object MUST return the Job object's REQUIRED "job-

state" attribute. The value of this attribute (along with the

value of the next attribute "job-state-reasons") is taken from a

"snapshot" of the new Job object at some meaningful point in

time (implementation defined) between when the Printer object

receives the Print-Job Request and when the Printer object

returns the response.

"job-state-reasons":

The Printer object OPTIONALLY returns the Job object's OPTIONAL

"job-state-reasons" attribute. If the Printer object supports

this attribute then it MUST be returned in the response. If

this attribute is not returned in the response, the client can

assume that the "job-state-reasons" attribute is not supported

and will not be returned in a subsequent Job object query.

"job-state-message":

The Printer object OPTIONALLY returns the Job object's OPTIONAL

"job-state-message" attribute. If the Printer object supports

this attribute then it MUST be returned in the response. If

this attribute is not returned in the response, the client can

assume that the "job-state-message" attribute is not supported

and will not be returned in a subsequent Job object query.

"number-of-intervening-jobs":

The Printer object OPTIONALLY returns the Job object's OPTIONAL

"number-of-intervening-jobs" attribute. If the Printer object

supports this attribute then it MUST be returned in the

response. If this attribute is not returned in the response,

the client can assume that the "number-of-intervening-jobs"

attribute is not supported and will not be returned in a

subsequent Job object query.

Note: Since any printer state information which affects a job's

state is reflected in the "job-state" and "job-state-reasons"

attributes, it is sufficient to return only these attributes and

no specific printer status attributes.

Note: In addition to the MANDATORY parameters required for every

operation response, the simplest response consists of the just the

"attributes-charset" and "attributes-natural-language" operation

attributes and the "job-uri", "job-id", and "job-state" Job Object

Attributes. In this simplest case, the status code is "successful-

ok" and there is no "status-message" operation attribute.

3.2.2 Print-URI Operation

This OPTIONAL operation is identical to the Print-Job operation

(section 3.2.1) except that a client supplies a URI reference to the

document data using the "document-uri" (uri) operation attribute (in

Group 1) rather than including the document data itself. Before

returning the response, the Printer MUST validate that the Printer

supports the retrieval method (e.g., http, FTP, etc.) implied by the

URI, and MUST check for valid URI syntax. If the client-supplied URI

scheme is not supported, i.e. the value is not in the Printer

object's "referenced-uri-scheme-supported" attribute, the Printer

object MUST reject the request and return the 'client-error-uri-

scheme-not-supported' status code. See The Implementer's Guide

[ipp-iig] for suggested additional checks. The Printer NEED NOT

follow the reference and validate the contents of the reference.

If the Printer object supports this operation, it MUST support the

"reference-uri-schemes-supported" Printer attribute (see section

4.4.24).

It is up to the IPP object to interpret the URI and subsequently

"pull" the document from the source referenced by the URI string.

3.2.3 Validate-Job Operation

This REQUIRED operation is similar to the Print-Job operation

(section 3.2.1) except that a client supplies no document data and

the Printer allocates no resources (i.e., it does not create a new

Job object). This operation is used only to verify capabilities of a

printer object against whatever attributes are supplied by the client

in the Validate-Job request. By using the Validate-Job operation a

client can validate that an identical Print-Job operation (with the

document data) would be accepted. The Validate-Job operation also

performs the same security negotiation as the Print-Job operation

(see section 8), so that a client can check that the client and

Printer object security requirements can be met before performing a

Print-Job operation.

Note: The Validate-Job operation does not accept a "document-uri"

attribute in order to allow a client to check that the same Print-URI

operation will be accepted, since the client doesn't send the data

with the Print-URI operation. The client SHOULD just issue the

Print-URI request.

The Printer object returns the same status codes, Operation

Attributes (Group 1) and Unsupported Attributes (Group 2) as the

Print-Job operation. However, no Job Object Attributes (Group 3) are

returned, since no Job object is created.

3.2.4 Create-Job Operation

This OPTIONAL operation is similar to the Print-Job operation

(section 3.2.1) except that in the Create-Job request, a client does

not supply document data or any reference to document data. Also,

the client does not supply any of the "document-name", "document-

format", "compression", or "document-natural-language" operation

attributes. This operation is followed by one or more Send-Document

or Send-URI operations. In each of those operation requests, the

client OPTIONALLY supplies the "document-name", "document-format",

and "document-natural-language" attributes for each document in the

multi-document Job object.

If a Printer object supports the Create-Job operation, it MUST also

support the Send-Document operation and also MAY support the Send-URI

operation.

If the Printer object supports this operation, it MUST support the

"multiple-operation-time-out" Printer attribute (see section 4.4.28).

3.2.5 Get-Printer-Attributes Operation

This REQUIRED operation allows a client to request the values of the

attributes of a Printer object. In the request, the client supplies

the set of Printer attribute names and/or attribute group names in

which the requester is interested. In the response, the Printer

object returns a corresponding attribute set with the appropriate

attribute values filled in.

For Printer objects, the possible names of attribute groups are:

- 'job-template': all of the Job Template attributes that apply to

a Printer object (the last two columns of the table in Section

4.2).

- 'printer-description': the attributes specified in Section 4.4.

- 'all': the special group 'all' that includes all supported

attributes.

Since a client MAY request specific attributes or named groups, there

is a potential that there is some overlap. For example, if a client

requests, 'printer-name' and 'all', the client is actually requesting

the "printer-name" attribute twice: once by naming it explicitly, and

once by inclusion in the 'all' group. In such cases, the Printer

object NEED NOT return each attribute only once in the response even

if it is requested multiple times. The client SHOULD NOT request the

same attribute in multiple ways.

It is NOT REQUIRED that a Printer object support all attributes

belonging to a group (since some attributes are OPTIONAL). However,

it is REQUIRED that each Printer object support all group names.

3.2.5.1 Get-Printer-Attributes Request

The following sets of attributes are part of the Get-Printer-

Attributes Request:

Group 1: Operation Attributes

Natural Language and Character Set:

attributes-charset" and "attributes-natural-language" butes as

described in section 3.1.4.1.

Target:

The "printer-uri" (uri) operation attribute which is the target

for this operation as described in section 3.1.5.

Requesting User Name:

The "requesting-user-name" (name(MAX)) attribute SHOULD be

supplied by the client as described in section 8.3.

"requested-attributes" (1setOf keyword) :

The client OPTIONALLY supplies a set of attribute names and/or

attribute group names in whose values the requester is

interested. The Printer object MUST support this attribute. If

the client omits this attribute, the Printer MUST respond as if

this attribute had been supplied with a value of 'all'.

"document-format" (mimeMediaType) :

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. This attribute is useful

for a Printer object to determine the set of supported attribute

values that relate to the requested document format. The

Printer object MUST return the attributes and values that it

uses to validate a job on a create or Validate-Job operation in

which this document format is supplied. The Printer object

SHOULD return only (1) those attributes that are supported for

the specified format and (2) the attribute values that are

supported for the specified document format. By specifying the

document format, the client can get the Printer object to

eliminate the attributes and values that are not supported for a

specific document format. For example, a Printer object might

have multiple interpreters to support both '

application/postscript' (for PostScript) and 'text/plain' (for

text) documents. However, for only one of those interpreters

might the Printer object be able to support "number-up" with

values of '1', '2', and '4'. For the other interpreter it might

be able to only support "number-up" with a value of '1'. Thus a

client can use the Get-Printer-Attributes operation to obtain

the attributes and values that will be used to accept/reject a

create job operation.

If the Printer object does not distinguish between different

sets of supported values for each different document format when

validating jobs in the create and Validate-Job operations, it

MUST NOT distinguish between different document formats in the

Get-Printer-Attributes operation. If the Printer object does

distinguish between different sets of supported values for each

different document format specified by the client, this

specialization applies only to the following Printer object

attributes:

- Printer attributes that are Job Template attributes ("xxx-

default" "xxx-supported", and "xxx-ready" in the Table in

Section 4.2),

- "pdl-override-supported",

- "compression-supported",

- "job-k-octets-supported",

- "job-impressions-supported,

- "job-media-sheets-supported"

- "printer-driver-installer",

- "color-supported", and

- "reference-uri-schemes-supported"

The values of all other Printer object attributes (including

"document-format-supported") remain invariant with respect to

the client supplied document format (except for new Printer

description attribute as registered according to section 6.2).

If the client omits this "document-format" operation attribute,

the Printer object MUST respond as if the attribute had been

supplied with the value of the Printer object's "document-

format-default" attribute. It is recommended that the client

always supply a value for "document-format", since the Printer

object's "document-format-default" may be 'application/octet-

stream', in which case the returned attributes and values are

for the union of the document formats that the Printer can

automatically sense. For more details, see the description of

the 'mimeMediaType' attribute syntax in section 4.1.9.

If the client supplies a value for the "document-format"

Operation attribute that is not supported by the Printer, i.e.,

is not among the values of the Printer object's "document-

format-supported" attribute, the Printer object MUST reject the

operation and return the 'client-error-document-format-not-

supported' status code.

3.2.5.2 Get-Printer-Attributes Response

The Printer object returns the following sets of attributes as part

of the Get-Printer-Attributes Response:

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in section 3.1.6.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2.

Group 2: Unsupported Attributes

This is a set of Operation attributes supplied by the client (in

the request) that are not supported by the Printer object or

that conflict with one another (see sections 3.2.1.2 and 16).

The response NEED NOT contain the "requested-attributes"

operation attribute with any supplied values (attribute

keywords) that were requested by the client but are not

supported by the IPP object. If the Printer object is not

returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Group 3: Printer Object Attributes

This is the set of requested attributes and their current

values. The Printer object ignores (does not respond with) any

requested attribute which is not supported. The Printer object

MAY respond with a subset of the supported attributes and

values, depending on the security policy in force. However, the

Printer object MUST respond with the 'unknown' value for any

supported attribute (including all REQUIRED attributes) for

which the Printer object does not know the value. Also the

Printer object MUST respond with the 'no-value' for any

supported attribute (including all REQUIRED attributes) for

which the system administrator has not configured a value. See

the description of the "out-of-band" values in the beginning of

Section 4.1.

3.2.6 Get-Jobs Operation

This REQUIRED operation allows a client to retrieve the list of Job

objects belonging to the target Printer object. The client may also

supply a list of Job attribute names and/or attribute group names. A

group of Job object attributes will be returned for each Job object

that is returned.

This operation is similar to the Get-Job-Attributes operation, except

that this Get-Jobs operation returns attributes from possibly more

than one object (see the description of Job attribute group names in

section 3.3.4).

3.2.6.1 Get-Jobs Request

The client submits the Get-Jobs request to a Printer object.

The following groups of attributes are part of the Get-Jobs Request:

Group 1: Operation Attributes

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.1.

Target:

The "printer-uri" (uri) operation attribute which is the target

for this operation as described in section 3.1.5.

Requesting User Name:

The "requesting-user-name" (name(MAX)) attribute SHOULD be

supplied by the client as described in section 8.3.

"limit" (integer(1:MAX)):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It is an integer value that

indicates a limit to the number of Job objects returned. The

limit is a "stateless limit" in that if the value supplied by

the client is 'N', then only the first 'N' jobs are returned in

the Get-Jobs Response. There is no mechanism to allow for the

next 'M' jobs after the first 'N' jobs. If the client does not

supply this attribute, the Printer object responds with all

applicable jobs.

"requested-attributes" (1setOf keyword):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It is a set of Job

attribute names and/or attribute groups names in whose values

the requester is interested. This set of attributes is returned

for each Job object that is returned. The allowed attribute

group names are the same as those defined in the Get-Job-

Attributes operation in section 3.3.4. If the client does not

supply this attribute, the Printer MUST respond as if the client

had supplied this attribute with two values: 'job-uri' and '

job-id'.

"which-jobs" (type2 keyword):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It indicates which Job

objects MUST be returned by the Printer object. The values for

this attribute are:

'completed': This includes any Job object whose state is

'completed', 'canceled', or 'aborted'.

'not-completed': This includes any Job object whose state is '

pending', 'processing', 'processing-stopped', or 'pending-

held'.

A Printer object MUST support both values. However, if the

mentation does not keep jobs in the 'completed', 'canceled', '

aborted' states, then it returns no jobs when the 'completed'

value is supplied.

If a client supplies some other value, the Printer object MUST

copy the attribute and the unsupported value to the Unsupported

Attributes response group, reject the request, and return the '

client-error-attributes-or-values-not-supported' status code.

If the client does not supply this attribute, the Printer object

MUST respond as if the client had supplied the attribute with a

value of 'not-completed'.

"my-jobs" (boolean):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It indicates whether all

jobs or just the jobs submitted by the requesting user of this

request MUST be returned by the Printer object. If the client

does not supply this attribute, the Printer object MUST respond

as if the client had supplied the attribute with a value of '

false', i.e., all jobs. The means for authenticating the

requesting user and matching the jobs is described in section 8.

3.2.6.2 Get-Jobs Response

The Printer object returns all of the Job objects that match the

criteria as defined by the attribute values supplied by the client in

the request. It is possible that no Job objects are returned since

there may literally be no Job objects at the Printer, or there may be

no Job objects that match the criteria supplied by the client. If

the client requests any Job attributes at all, there is a set of Job

Object Attributes returned for each Job object.

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in sections 14 and

3.1.6.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2.

Group 2: Unsupported Attributes

This is a set of Operation attributes supplied by the client (in

the request) that are not supported by the Printer object or

that conflict with one another (see sections 3.2.1.2 and the

Implementer's Guide [ipp-iig]). The response NEED NOT contain

the "requested-attributes" operation attribute with any supplied

values (attribute keywords) that were requested by the client

but are not supported by the IPP object. If the Printer object

is not returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Groups 3 to N: Job Object Attributes

The Printer object responds with one set of Job Object

Attributes for each returned Job object. The Printer object

ignores (does not respond with) any requested attribute or value

which is not supported or which is restricted by the security

policy in force, including whether the requesting user is the

user that submitted the job (job originating user) or not (see

section 8). However, the Printer object MUST respond with the '

unknown' value for any supported attribute (including all

REQUIRED attributes) for which the Printer object does not know

the value, unless it would violate the security policy. See the

description of the "out-of-band" values in the beginning of

Section 4.1.

Jobs are returned in the following order:

- If the client requests all 'completed' Jobs (Jobs in the '

completed', 'aborted', or 'canceled' states), then the Jobs

are returned newest to oldest (with respect to actual

completion time)

- If the client requests all 'not-completed' Jobs (Jobs in the

'pending', 'processing', 'pending-held', and 'processing-

stopped' states), then Jobs are returned in relative

chronological order of expected time to complete (based on

whatever scheduling algorithm is configured for the Printer

object).

3.3 Job Operations

All Job operations are directed at Job objects. A client MUST always

supply some means of identifying the Job object in order to identify

the correct target of the operation. That job identification MAY

either be a single Job URI or a combination of a Printer URI with a

Job ID. The IPP object implementation MUST support both forms of

identification for every job.

3.3.1 Send-Document Operation

This OPTIONAL operation allows a client to create a multi-document

Job object that is initially "empty" (contains no documents). In the

Create-Job response, the Printer object returns the Job object's URI

(the "job-uri" attribute) and the Job object's 32-bit identifier (the

"job-id" attribute). For each new document that the client desires

to add, the client uses a Send-Document operation. Each Send-

Document Request contains the entire stream of document data for one

document.

Since the Create-Job and the send operations (Send-Document or Send-

URI operations) that follow could occur over an arbitrarily long

period of time for a particular job, a client MUST send another send

operation within an IPP Printer defined minimum time interval after

the receipt of the previous request for the job. If a Printer object

supports multiple document jobs, the Printer object MUST support the

"multiple-operation-time-out" attribute (see section 4.4.28). This

attribute indicates the minimum number of seconds the Printer object

will wait for the next send operation before taking some recovery

action.

An IPP object MUST recover from an errant client that does not supply

a send operation, sometime after the minimum time interval specified

by the Printer object's "multiple-operation-time-out" attribute.

Such recovery MAY include any of the following or other recovery

actions:

1. Assume that the Job is an invalid job, start the process of

changing the job state to 'aborted', add the 'aborted-by-system'

value to the job's "job-state-reasons" attribute (see section

4.3.8), if supported, and clean up all resources associated with

the Job. In this case, if another send operation is finally

received, the Printer responds with an "client-error-not-

possible" or "client-error-not-found" depending on whether or

not the Job object is still around when the send operation

finally arrives.

2. Assume that the last send operation received was in fact the

last document (as if the "last-document" flag had been set to '

true'), close the Job object, and proceed to process it (i.e.,

move the Job's state to 'pending').

3. Assume that the last send operation received was in fact the

last document, close the Job, but move it to the 'pending-held'

and add the 'submission-interrupted' value to the job's "job-

state-reasons" attribute (see section 4.3.8), if supported.

This action allows the user or an operator to determine whether

to continue processing the Job by moving it back to the '

pending' state or to cancel the job.

Each implementation is free to decide the "best" action to take

depending on local policy, whether any documents have been added,

whether the implementation spools jobs or not, and/or any other piece

of information available to it. If the choice is to abort the Job

object, it is possible that the Job object may already have been

processed to the point that some media sheet pages have been printed.

3.3.1.1 Send-Document Request

The following attribute sets are part of the Send-Document Request:

Group 1: Operation Attributes

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.1.

Target:

Either (1) the "printer-uri" (uri) plus "job-id"

(integer(1:MAX))or (2) the "job-uri" (uri) operation

attribute(s) which define the target for this operation as

described in section 3.1.5.

Requesting User Name:

"requesting-user-name" (name(MAX)) attribute SHOULD be supplied

by the client as described in section 8.3.

"document-name" (name(MAX)):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. It contains the client

supplied document name. The document name MAY be different than

the Job name. It might be helpful, but NEED NOT be unique

across multiple documents in the same Job. Typically, the

client software automatically supplies the document name on

behalf of the end user by using a file name or an application

generated name. See the description of the "document-name"

operation attribute in the Print-Job Request (section 3.2.1.1)

for more information about this attribute

"document-format" (mimeMediaType):

The client OPTIONALLY supplies this attribute. The Printer

object MUST support this attribute. The value of this attribute

identifies the format of the supplied document data. If the

client does not supply this attribute, the Printer object

assumes that the document data is in the format defined by the

Printer object's "document-format-default" attribute. If the

client supplies this attribute, but the value is not supported

by the Printer object, i.e., the value is not one of the values

of the Printer object's "document-format-supported" attribute,

the Printer object MUST reject the request and return the '

client-error-document-format-not-supported' status code.

"document-natural-language" (naturalLanguage):

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute. This attribute

specifies the natural language of the document for those

document-formats that require a specification of the natural

language in order to image the document unambiguously. There

are no particular values required for the Printer object to

support.

"compression" (type3 keyword)

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute and the "compression-

supported" attribute (see section 4.4.29). The client supplied

"compression" operation attribute identifies the compression

algorithm used on the document data. If the client omits this

attribute, the Printer object MUST assume that the data is not

compressed. If the client supplies the attribute and the

Printer object supports the attribute, the Printer object MUST

use the corresponding decompression algorithm on the document

data. If the client supplies this attribute, but the value is

not supported by the Printer object, i.e., the value is not one

of the values of the Printer object's "compression-supported"

attribute, the Printer object MUST copy the attribute and its

value to the Unsupported Attributes response group, reject the

request, and return the 'client-error-attributes-or-values-not-

supported' status code.

"last-document" (boolean):

The client MUST supply this attribute. The Printer object MUST

support this attribute. It is a boolean flag that is set to '

true' if this is the last document for the Job, 'false'

otherwise.

Group 2: Document Content

The client MUST supply the document data if the "last-document"

flag is set to 'false'. However, since a client might not know

that the previous document sent with a Send-Document (or Send-

URI) operation was the last document (i.e., the "last-document"

attribute was set to 'false'), it is legal to send a Send-

Document request with no document data where the "last-document"

flag is set to 'true'. Such a request MUST NOT increment the

value of the Job object's "number-of-documents" attribute, since

no real document was added to the job.

3.3.1.2 Send-Document Response

The following sets of attributes are part of the Send-Document

Response:

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in sections 14 and

3.1.6.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2.

Group 2: Unsupported Attributes

This is a set of Operation attributes supplied by the client (in

the request) that are not supported by the Printer object or

that conflict with one another (see sections 3.2.1.2 and the

Implementer's Guide [ipp-iig]). If the Printer object is not

returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Group 3: Job Object Attributes

This is the same set of attributes as described in the Print-Job

response (see section 3.2.1.2).

3.3.2 Send-URI Operation

This OPTIONAL operation is identical to the Send-Document operation

(see section 3.3.1) except that a client MUST supply a URI reference

("document-uri" operation attribute) rather than the document data

itself. If a Printer object supports this operation, clients can use

both Send-URI or Send-Document operations to add new documents to an

existing multi-document Job object. However, if a client needs to

indicate that the previous Send-URI or Send-Document was the last

document, the client MUST use the Send-Document operation with no

document data and the "last-document" flag set to 'true' (rather than

using a Send-URI operation with no "document-uri" operation

attribute).

If a Printer object supports this operation, it MUST also support the

Print-URI operation (see section 3.2.2).

The Printer object MUST validate the syntax and URI scheme of the

supplied URI before returning a response, just as in the Print-URI

operation.

3.3.3 Cancel-Job Operation

This REQUIRED operation allows a client to cancel a Print Job from

the time the job is created up to the time it is completed, canceled,

or aborted. Since a Job might already be printing by the time a

Cancel-Job is received, some media sheet pages might be printed

before the job is actually terminated.

3.3.3.1 Cancel-Job Request

The following groups of attributes are part of the Cancel-Job

Request:

Group 1: Operation Attributes

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.1.

Target:

Either (1) the "printer-uri" (uri) plus "job-id"

(integer(1:MAX))or (2) the "job-uri" (uri) operation

attribute(s) which define the target for this operation as

described in section 3.1.5.

Requesting User Name:

The "requesting-user-name" (name(MAX)) attribute SHOULD be

supplied by the client as described in section 8.3.

"message" (text(127)):

The client OPTIONALLY supplies this attribute. The Printer

object OPTIONALLY supports this attribute. It is a message to

the operator. This "message" attribute is not the same as the

"job-message-from-operator" attribute. That attribute is used

to report a message from the operator to the end user that

queries that attribute. This "message" operation attribute is

used to send a message from the client to the operator along

with the operation request. It is an implementation decision of

how or where to display this message to the operator (if at

all).

3.3.3.2 Cancel-Job Response

The following sets of attributes are part of the Cancel-Job Response:

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in sections 14 and

3.1.6.

If the job is already in the 'completed', 'aborted', or '

canceled' state, or the 'process-to-stop-point' value is set in

the Job's "job-state-reasons" attribute, the Printer object MUST

reject the request and return the 'client-error-not-possible'

error status code.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2.

Group 2: Unsupported Attributes

This is a set of Operation attributes supplied by the client (in

the request) that are not supported by the Printer object or

that conflict with one another (see section 3.2.1.2 and the

Implementer's Guide [ipp-iig]). If the Printer object is not

returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Once a successful response has been sent, the implementation

guarantees that the Job will eventually end up in the 'canceled'

state. Between the time of the Cancel-Job operation is accepted and

when the job enters the 'canceled' job-state (see section 4.3.7), the

"job-state-reasons" attribute SHOULD contain the 'processing-to-

stop-point' value which indicates to later queries that although the

Job might still be 'processing', it will eventually end up in the '

canceled' state, not the 'completed' state.

3.3.4 Get-Job-Attributes Operation

This REQUIRED operation allows a client to request the values of

attributes of a Job object and it is almost identical to the Get-

Printer-Attributes operation (see section 3.2.5). The only

differences are that the operation is directed at a Job object rather

than a Printer object, there is no "document-format" operation

attribute used when querying a Job object, and the returned attribute

group is a set of Job object attributes rather than a set of Printer

object attributes.

For Jobs, the possible names of attribute groups are:

- 'job-template': all of the Job Template attributes that apply to a

Job object (the first column of the table in Section 4.2).

- 'job-description': all of the Job Description attributes specified

in Section 4.3.

- 'all': the special group 'all' that includes all supported

attributes.

Since a client MAY request specific attributes or named groups, there

is a potential that there is some overlap. For example, if a client

requests, 'job-name' and 'job-description', the client is actually

requesting the "job-name" attribute once by naming it explicitly, and

once by inclusion in the 'job-description' group. In such cases, the

Printer object NEED NOT return the attribute only once in the

response even if it is requested multiple times. The client SHOULD

NOT request the same attribute in multiple ways.

It is NOT REQUIRED that a Job object support all attributes belonging

to a group (since some attributes are OPTIONAL). However it is

REQUIRED that each Job object support all group names.

3.3.4.1 Get-Job-Attributes Request

The following groups of attributes are part of the Get-Job-Attributes

Request when the request is directed at a Job object:

Group 1: Operation Attributes

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.1.

Target:

Either (1) the "printer-uri" (uri) plus "job-id"

(integer(1:MAX)) or (2) the "job-uri" (uri) operation

attribute(s) which define the target for this operation as

described in section 3.1.5.

Requesting User Name:

The "requesting-user-name" (name(MAX)) attribute SHOULD be

supplied by the client as described in section 8.3.

"requested-attributes" (1setOf keyword) :

The client OPTIONALLY supplies this attribute. The IPP object

MUST support this attribute. It is a set of attribute names

and/or attribute group names in whose values the requester is

interested. If the client omits this attribute, the IPP object

MUST respond as if this attribute had been supplied with a value

of 'all'.

3.3.4.2 Get-Job-Attributes Response

The Printer object returns the following sets of attributes as part

of the Get-Job-Attributes Response:

Group 1: Operation Attributes

Status Message:

In addition to the REQUIRED status code returned in every

response, the response OPTIONALLY includes a "status-message"

(text) operation attribute as described in sections 14 and

3.1.6.

Natural Language and Character Set:

The "attributes-charset" and "attributes-natural-language"

attributes as described in section 3.1.4.2. The "attributes-

natural-language" MAY be the natural language of the Job object,

rather than the one requested.

Group 2: Unsupported Attributes

This is a set of Operation attributes supplied by the client (in

the request) that are not supported by the Printer object or

that conflict with one another (see sections 3.2.1.2 and the

Implementer's Guide [ipp-iig]). The response NEED NOT contain

the "requested-attributes" operation attribute with any supplied

values (attribute keywords) that were requested by the client

but are not supported by the IPP object. If the Printer object

is not returning any Unsupported Attributes in the response, the

Printer object SHOULD omit Group 2 rather than sending an empty

group. However, a client MUST be able to accept an empty group.

Group 3: Job Object Attributes

This is the set of requested attributes and their current

values. The IPP object ignores (does not respond with) any

requested attribute or value which is not supported or which is

restricted by the security policy in force, including whether

the requesting user is the user that submitted the job (job

originating user) or not (see section 8). However, the IPP

object MUST respond with the 'unknown' value for any supported

attribute (including all RED butes) for which the IPP object

does not know the value, s it would violate the security policy.

See the description e "out-of-band" values in the beginning of

Section 4.1.

4. Object Attributes

This section describes the attributes with their corresponding

attribute syntaxes and values that are part of the IPP model. The

sections below show the objects and their associated attributes which

are included within the scope of this protocol. Many of these

attributes are derived from other relevant specifications:

- Document Printing Application (DPA) [ISO10175]

- RFC1759 Printer MIB [RFC1759]

Each attribute is uniquely identified in this document using a

"keyword" (see section 12.2.1) which is the name of the attribute.

The keyword is included in the section header describing that

attribute.

Note: Not only are keywords used to identify attributes, but one of

the attribute syntaxes described below is "keyword" so that some

attributes have keyword values. Therefore, these attributes are

defined as having an attribute syntax that is a set of keywords.

4.1 Attribute Syntaxes

This section defines the basic attribute syntax types that all clients

and IPP objects MUST be able to accept in responses and accept in

requests, respectively. Each attribute description in sections 3 and

4 includes the name of attribute syntax(es) in the heading (in

parentheses). A conforming implementation of an attribute MUST

include the semantics of the attribute syntax(es) so identified.

Section 6.3 describes how the protocol can be extended with new

attribute syntaxes.

The attribute syntaxes are specified in the following sub-sections,

where the sub-section heading is the keyword name of the attribute

syntax inside the single quotes. In operation requests and responses

each attribute value MUST be represented as one of the attribute

syntaxes specified in the sub-section heading for the attribute. In

addition, the value of an attribute in a response (but not in a

request) MAY be one of the "out-of-band" values. Standard

"out-of-band" values are:

'unknown': The attribute is supported by the IPP object, but the

value is unknown to the IPP object for some reason.

'unsupported': The attribute is unsupported by the IPP object. This

value MUST be returned only as the value of an attribute in the

Unsupported Attributes Group.

'no-value': The attribute is supported by the Printer object, but

the system administrator has not yet configured a value.

The Encoding and Transport specification [RFC2565] defines mechanisms

for passing "out-of-band" values. All attributes in a request MUST

have one or more values as defined in Sections 4.2 to 4.4. Thus

clients MUST NOT supply attributes with "out-of-band" values. All

attribute in a response MUST have one or more values as defined in

Sections 4.2 to 4.4 or a single "out-of-band" value.

Most attributes are defined to have a single attribute syntax.

However, a few attributes (e.g., "job-sheet", "media", "job-hold-

until") are defined to have several attribute syntaxes, depending on

the value. These multiple attribute syntaxes are separated by the

"" character in the sub-section heading to indicate the choice.

Since each value MUST be tagged as to its attribute syntax in the

protocol, a single-valued attribute instance may have any one of its

attribute syntaxes and a multi-valued attribute instance may have a

mixture of its defined attribute syntaxes.

4.1.1 'text'

A text attribute is an attribute whose value is a sequence of zero or

more characters encoded in a maximum of 1023 ('MAX') octets. MAX is

the maximum length for each value of any text attribute. However, if

an attribute will always contain values whose maximum length is much

less than MAX, the definition of that attribute will include a

qualifier that defines the maximum length for values of that

attribute. For example: the "printer-location" attribute is

specified as "printer-location (text(127))". In this case, text

values for "printer-location" MUST NOT exceed 127 octets; if supplied

with a longer text string via some external interface (other than the

protocol), implementations are free to truncate to this shorter

length limitation.

In this specification, all text attributes are defined using the '

text' syntax. However, 'text' is used only for brevity; the formal

interpretation of 'text' is: 'textWithoutLanguage

textWithLanguage'. That is, for any attribute defined in this

specification using the 'text' attribute syntax, all IPP objects and

clients MUST support both the 'textWithoutLanguage' and '

textWithLanguage' attribute syntaxes. However, in actual usage and

protocol execution, objects and clients accept and return only one of

the two syntax per attribute. The syntax 'text' never appears "on-

the-wire".

Both 'textWithoutLanguage' and 'textWithLanguage' are needed to

support the real world needs of interoperability between sites and

systems that use different natural languages as the basis for human

communication. Generally, one natural language applies to all text

attributes in a given request or response. The language is indicated

by the "attributes-natural-language" operation attribute defined in

section 3.1.4 or "attributes-natural-language" job attribute defined

in section 4.3.24, and there is no need to identify the natural

language for each text string on a value-by-value basis. In these

cases, the attribute syntax 'textWithoutLanguage' is used for text

attributes. In other cases, the client needs to supply or the

Printer object needs to return a text value in a natural language

that is different from the rest of the text values in the request or

response. In these cases, the client or Printer object uses the

attribute syntax 'textWithLanguage' for text attributes (this is the

Natural Language Override mechanism described in section 3.1.4).

The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes

are described in more detail in the following sections.

4.1.1.1 'textWithoutLanguage'

The 'textWithoutLanguage' syntax indicates a value that is sequence

of zero or more characters. Text strings are encoded using the rules

of some charset. The Printer object MUST support the UTF-8 charset

[RFC2279] and MAY support additional charsets to represent 'text'

values, provided that the charsets are registered with IANA [IANA-

CS]. See Section 4.1.7 for the specification of the 'charset'

attribute syntax, including restricted semantics and examples of

charsets.

4.1.1.2 'textWithLanguage'

The 'textWithLanguage' attribute syntax is a compound attribute

syntax consisting of two parts: a 'textWithoutLanguage' part plus an

additional 'naturalLanguage' (see section 4.1.8) part that overrides

the natural language in force. The 'naturalLanguage' part explicitly

identifies the natural language that applies to the text part of that

value and that value alone. For any give text attribute, the '

textWithoutLanguage' part is limited to the maximum length defined

for that attribute, but the 'naturalLanguage' part is always limited

to 63 octets. Using the 'textWithLanguage' attribute syntax rather

than the normal 'textWithoutLanguage' syntax is the so-called Natural

Language Override mechanism and MUST be supported by all IPP objects

and clients.

If the attribute is multi-valued (1setOf text), then the '

textWithLanguage' attribute syntax MUST be used to explicitly specify

each attribute value whose natural language needs to be overridden.

Other values in a multi-valued 'text' attribute in a request or a

response revert to the natural language of the operation attribute.

In a create request, the Printer object MUST accept and store with

the Job object any natural language in the "attributes-natural-

language" operation attribute, whether the Printer object supports

that natural language or not. Furthermore, the Printer object MUST

accept and store any 'textWithLanguage' attribute value, whether the

Printer object supports that natural language or not. These

requirements are independent of the value of the "ipp-attribute-

fidelity" operation attribute that the client MAY supply.

Example: If the client supplies the "attributes-natural-language"

operation attribute with the value: 'en' indicating English, but the

value of the "job-name" attribute is in French, the client MUST use

the 'textWithLanguage' attribute syntax with the following two

values:

'fr': Natural Language Override indicating French

'Rapport Mensuel': the job name in French

See the Encoding and Transport document [RFC2565] for a detailed

example of the 'textWithLanguage' attribute syntax.

4.1.2 'name'

This syntax type is used for user-friendly strings, such as a Printer

name, that, for humans, are more meaningful than identifiers. Names

are never translated from one natural language to another. The '

name' attribute syntax is essentially the same as 'text', including

the REQUIRED support of UTF-8 except that the sequence of characters

is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.

Also like 'text', 'name' is really an abbreviated notation for either

'nameWithoutLanguage' or 'nameWithLanguage'. That is, all IPP

objects and clients MUST support both the 'nameWithoutLanguage' and '

nameWithLanguage' attribute syntaxes. However, in actual usage and

protocol execution, objects and clients accept and return only one of

the two syntax per attribute. The syntax 'name' never appears "on-

the-wire".

Note: Only the 'text' and 'name' attribute syntaxes permit the

Natural Language Override mechanism.

Some attributes are defined as 'type3 keyword name'. These

attributes support values that are either type3 keywords or names.

This dual-syntax mechanism enables a site administrator to extend

these attributes to legally include values that are locally defined

by the site administrator. Such names are not registered with IANA.

4.1.2.1 'nameWithoutLanguage'

The 'nameWithoutLanguage' syntax indicates a value that is sequence

of zero or more characters so that its encoded form does not exceed

MAX octets.

4.1.2.2 'nameWithLanguage'

The 'nameWithLanguage' attribute syntax is a compound attribute

syntax consisting of two parts: a 'nameWithoutLanguage' part plus an

additional 'naturalLanguage' (see section 4.1.8) part that overrides

the natural language in force. The 'naturalLanguage' part explicitly

identifies the natural language that applies to that name value and

that name value alone.

The 'nameWithLanguage' attribute syntax behaves the same as the '

textWithLanguage' syntax. If a name is in a language that is

different than the rest of the object or operation, then this '

nameWithLanguage' syntax is used rather than the generic '

nameWithoutLanguage' syntax.

Example: If the client supplies the "attributes-natural-language"

operation attribute with the value: 'en' indicating English, but the

"printer-name" attribute is in German, the client MUST use the '

nameWithLanguage' attribute syntax as follows:

'de': Natural Language Override indicating German

'Farbdrucker': the Printer name in German

4.1.2.3 Matching 'name' attribute values

For purposes of matching two 'name' attribute values for equality,

such as in job validation (where a client-supplied value for

attribute "xxx" is checked to see if the value is among the values of

the Printer object's corresponding "xxx-supported" attribute), the

following match rules apply:

1. 'keyword' values never match 'name' values.

2. 'name' (nameWithoutLanguage and nameWithLanguage) values

match if (1) the name parts match and (2) the Associated

Natural-Language parts (see section 3.1.4.1) match. The

matching rules are:

a. the name parts match if the two names are identical

character by character, except it is RECOMMENDED that case

be ignored. For example: 'Ajax-letter-head-white' MUST

match 'Ajax-letter-head-white' and SHOULD match 'ajax-

letter-head-white' and 'AJAX-LETTER-HEAD-WHITE'.

b. the Associated Natural-Language parts match if the

shorter of the two meets the syntactic requirements of RFC

1766 [RFC1766] and matches byte for byte with the longer.

For example, 'en' matches 'en', 'en-us' and 'en-gb', but

matches neither 'fr' nor 'e'.

4.1.3 'keyword'

The 'keyword' attribute syntax is a sequence of characters, length: 1

to 255, containing only the US-ASCII [ASCII] encoded values for

lowercase letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot

("."), and underscore ("_"). The first character MUST be a lowercase

letter. Furthermore, keywords MUST be in U.S. English.

This syntax type is used for enumerating semantic identifiers of

entities in the abstract protocol, i.e., entities identified in this

document. Keywords are used as attribute names or values of

attributes. Unlike 'text' and 'name' attribute values, 'keyword'

values MUST NOT use the Natural Language Override mechanism, since

they MUST always be US-ASCII and U.S. English.

Keywords are for use in the protocol. A user interface will likely

provide a mapping between protocol keywords and displayable user-

friendly words and phrases which are localized to the natural

language of the user. While the keywords specified in this document

MAY be displayed to users whose natural language is U.S. English,

they MAY be mapped to other U.S. English words for U.S. English

users, since the user interface is outside the scope of this

document.

In the definition for each attribute of this syntax type, the full

set of defined keyword values for that attribute are listed.

When a keyword is used to represent an attribute (its name), it MUST

be unique within the full scope of all IPP objects and attributes.

When a keyword is used to represent a value of an attribute, it MUST

be unique just within the scope of that attribute. That is, the same

keyword MUST NOT be used for two different values within the same

attribute to mean two different semantic ideas. However, the same

keyword MAY be used across two or more attributes, representing

different semantic ideas for each attribute. Section 6.1 describes

how the protocol can be extended with new keyword values. Examples

of attribute name keywords:

"job-name"

"attributes-charset"

Note: This document uses "type1", "type2", and "type3" prefixes to

the "keyword" basic syntax to indicate different levels of review for

extensions (see section 6.1).

4.1.4 'enum'

The 'enum' attribute syntax is an enumerated integer value that is in

the range from 1 to 2**31 - 1 (MAX). Each value has an associated '

keyword' name. In the definition for each attribute of this syntax

type, the full set of possible values for that attribute are listed.

This syntax type is used for attributes for which there are enum

values assigned by other standards, such as SNMP MIBs. A number of

attribute enum values in this specification are also used for

corresponding attributes in other standards [RFC1759]. This syntax

type is not used for attributes to which the system administrator may

assign values. Section 6.1 describes how the protocol can be

extended with new enum values.

Enum values are for use in the protocol. A user interface will

provide a mapping between protocol enum values and displayable user-

friendly words and phrases which are localized to the natural

language of the user. While the enum symbols specified in this

document MAY be displayed to users whose natural language is U.S.

English, they MAY be mapped to other U.S. English words for U.S.

English users, since the user interface is outside the scope of this

document.

Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP

"out-of-band" value 'unknown'. See the description of the "out-of-

band" values at the beginning of Section 4.1. Therefore, attributes

of type 'enum' start at '3'.

Note: This document uses "type1", "type2", and "type3" prefixes to

the "enum" basic syntax to indicate different levels of review for

extensions (see section 6.1).

4.1.5 'uri'

The 'uri' attribute syntax is any valid Uniform Resource Identifier

or URI [RFC2396]. Most often, URIs are simply Uniform Resource

Locators or URLs. The maximum length of URIs used as values of IPP

attributes is 1023 octets. Although most other IPP attribute syntax

types allow for only lower-cased values, this attribute syntax type

conforms to the case-sensitive and case-insensitive rules specified

in [RFC2396].

4.1.6 'uriScheme'

The 'uriScheme' attribute syntax is a sequence of characters

representing a URI scheme according to RFC2396 [RFC2396]. Though

RFC2396 requires that the values be case-insensitive, IPP requires

all lower case values in IPP attributes to simplify comparing by IPP

clients and Printer objects. Standard values for this syntax type

are the following keywords:

'http': for HTTP schemed URIs (e.g., "http:...")

'https': for use with HTTPS schemed URIs (e.g., "https:...")

(not on IETF standards track)

'ftp': for FTP schemed URIs (e.g., "ftp:...")

'mailto': for SMTP schemed URIs (e.g., "mailto:...")

'file': for file schemed URIs (e.g., "file:...")

A Printer object MAY support any URI 'scheme' that has been

registered with IANA [IANA-MT]. The maximum length of URI 'scheme'

values used to represent IPP attribute values is 63 octets.

4.1.7 'charset'

The 'charset' attribute syntax is a standard identifier for a

charset. A charset is a coded character set and encoding scheme.

Charsets are used for labeling certain document contents and 'text'

and 'name' attribute values. The syntax and semantics of this

attribute syntax are specified in RFC2046 [RFC2046] and contained in

the IANA character-set Registry [IANA-CS] according to the IANA

procedures [RFC2278]. Though RFC2046 requires that the values be

case-insensitive US-ASCII, IPP requires all lower case values in IPP

attributes to simplify comparing by IPP clients and Printer objects.

When a character-set in the IANA registry has more than one name

(alias), the name labeled as "(preferred MIME name)", if present,

MUST be used.

The maximum length of 'charset' values used to represent IPP

attribute values is 63 octets.

Some examples are:

'utf-8': ISO 10646 Universal Multiple-Octet Coded Character Set

(UCS) represented as the UTF-8 [RFC2279] transfer encoding

scheme in which US-ASCII is a subset charset.

'us-ascii': 7-bit American Standard Code for Information

Interchange (ASCII), ANSI X3.4-1986 [ASCII]. That standard

defines US-ASCII, but RFC2045 [RFC2045] eliminates most of the

control characters from conformant usage in MIME and IPP.

'iso-8859-1': 8-bit One-Byte Coded Character Set, Latin Alphabet

Nr 1 [ISO8859-1]. That standard defines a coded character set

that is used by Latin languages in the Western Hemisphere and

Western Europe. US-ASCII is a subset charset.

'iso-10646-ucs-2': ISO 10646 Universal Multiple-Octet Coded

Character Set (UCS) represented as two octets (UCS-2), with the

high order octet of each pair coming first (so-called Big Endian

integer).

Some attribute descriptions MAY place additional requirements on

charset values that may be used, such as REQUIRED values that MUST be

supported or additional restrictions, such as requiring that the

charset have US-ASCII as a subset charset.

4.1.8 'naturalLanguage'

The 'naturalLanguage' attribute syntax is a standard identifier for a

natural language and optionally a country. The values for this

syntax type are defined by RFC1766 [RFC1766]. Though RFC1766

requires that the values be case-insensitive US-ASCII, IPP requires

all lower case to simplify comparing by IPP clients and Printer

objects. Examples include:

'en': for English

'en-us': for US English

'fr': for French

'de': for German

The maximum length of 'naturalLanguage' values used to represent IPP

attribute values is 63 octets.

4.1.9 'mimeMediaType'

The 'mimeMediaType' attribute syntax is the Internet Media Type

(sometimes called MIME type) as defined by RFC2046 [RFC2046] and

registered according to the procedures of RFC2048 [RFC2048] for

identifying a document format. The value MAY include a charset

parameter, depending on the specification of the Media Type in the

IANA Registry [IANA-MT]. Although most other IPP syntax types allow

for only lower-cased values, this syntax type allows for mixed-case

values which are case-insensitive.

Examples are:

'text/Html': An HTML document

'text/plain': A plain text document in US-ASCII (RFC2046 indicates

that in the absence of the charset parameter MUST mean US-ASCII

rather than simply unspecified) [RFC2046].

'text/plain; charset=US-ASCII': A plain text document in US-ASCII

[52, 56].

'text/plain; charset=ISO-8859-1': A plain text document in ISO

8859-1 (Latin 1) [ISO8859-1].

'text/plain; charset=utf-8': A plain text document in ISO 10646

represented as UTF-8 [RFC2279]

'text/plain, charset=iso-10646-ucs-2': A plain text document in

ISO 10646 represented in two octets (UCS-2) [ISO10646-1]

'application/postscript': A PostScript document [RFC2046]

'application/vnd.hp-PCL': A PCL document [IANA-MT] (charset escape

sequence embedded in the document data)

'application/octet-stream': Auto-sense - see below

One special type is 'application/octet-stream'. If the Printer

object supports this value, the Printer object MUST be capable of

auto-sensing the format of the document data. If the Printer

object's default value attribute "document-format-default" is set to

'application/octet-stream', the Printer object not only supports

auto-sensing of the document format, but will depend on the result of

applying its auto-sensing when the client does not supply the

"document-format" attribute. If the client supplies a document

format value, the Printer MUST rely on the supplied attribute, rather

than trust its auto-sensing algorithm. To summarize:

1. If the client does not supply a document format value, the

Printer MUST rely on its default value setting (which may be '

application/octet-stream' indicating an auto-sensing mechanism).

2. If the client supplies a value other than 'application/octet-

stream', the client is supplying valid information about the

format of the document data and the Printer object MUST trust

the client supplied value more than the outcome of applying an

automatic format detection mechanism. For example, the client

may be requesting the printing of a PostScript file as a '

text/plain' document. The Printer object MUST print a text

representation of the PostScript commands rather than interpret

the stream of PostScript commands and print the result.

3. If the client supplies a value of 'application/octet-stream',

the client is indicating that the Printer object MUST use its

auto-sensing mechanism on the client supplied document data

whether auto-sensing is the Printer object's default or not.

Note: Since the auto-sensing algorithm is probabilistic, if the

client requests both auto-sensing ("document-format" set to '

application/octet-stream') and true fidelity ("ipp-attribute-

fidelity" set to 'true'), the Printer object might not be able to

guarantee exactly what the end user intended (the auto-sensing

algorithm might mistake one document format for another ), but it is

able to guarantee that its auto-sensing mechanism be used.

The maximum length of a 'mimeMediaType' value to represent IPP

attribute values is 255 octets.

4.1.10 'octetString'

The 'octetString' attribute syntax is a sequence of octets encoded in

a maximum of 1023 octets which is indicated in sub-section headers

using the notation: octetString(MAX). This syntax type is used for

opaque data.

4.1.11 'boolean'

The 'boolean' attribute syntax has only two values: 'true' and '

false'.

4.1.12 'integer'

The 'integer' attribute syntax is an integer value that is in the

range from -2**31 (MIN) to 2**31 - 1 (MAX). Each individual

attribute may specify the range constraint explicitly in sub-section

headers if the range is different from the full range of possible

integer values. For example: job-priority (integer(1:100)) for the

"job-priority" attribute. However, the enforcement of that

additional constraint is up to the IPP objects, not the protocol.

4.1.13 'rangeOfInteger'

The 'rangeOfInteger' attribute syntax is an ordered pair of integers

that defines an inclusive range of integer values. The first integer

specifies the lower bound and the second specifies the upper bound.

If a range constraint is specified in the header description for an

attribute in this document whose attribute syntax is 'rangeOfInteger'

(i.e., 'X:Y' indicating X as a minimum value and Y as a maximum

value), then the constraint applies to both integers.

4.1.14 'dateTime'

The 'dateTime' attribute syntax is a standard, fixed length, 11 octet

representation of the "DateAndTime" syntax as defined in RFC2579

[RFC2579]. RFC2579 also identifies an 8 octet representation of a

"DateAndTime" value, but IPP objects MUST use the 11 octet

representation. A user interface will provide a mapping between

protocol dateTime values and displayable user-friendly words or

presentation values and phrases which are localized to the natural

language and date format of the user.

4.1.15 'resolution'

The 'resolution' attribute syntax specifies a two-dimensional

resolution in the indicated units. It consists of 3 values: a cross

feed direction resolution (positive integer value), a feed direction

resolution (positive integer value), and a units value. The

semantics of these three components are taken from the Printer MIB

[RFC1759] suggested values. That is, the cross feed direction

component resolution component is the same as the

prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed

direction component resolution component is the same as the

prtMarkerAddressabilityFeedDir in the Printer MIB, and the units

component is the same as the prtMarkerAddressabilityUnit object in

the Printer MIB (namely, '3' indicates dots per inch and '4'

indicates dots per centimeter). All three values MUST be present

even if the first two values are the same. Example: '300', '600', '

3' indicates a 300 dpi cross-feed direction resolution, a 600 dpi

feed direction resolution, since a '3' indicates dots per inch (dpi).

4.1.16 '1setOf X'

The '1setOf X' attribute syntax is 1 or more values of attribute

syntax type X. This syntax type is used for multi-valued attributes.

The syntax type is called '1setOf' rather than just 'setOf' as a

reminder that the set of values MUST NOT be empty (i.e., a set of

size 0). Sets are normally unordered. However each attribute

description of this type may specify that the values MUST be in a

certain order for that attribute.

4.2 Job Template Attributes

Job Template attributes describe job processing behavior. Support

for Job Template attributes by a Printer object is OPTIONAL (see

section 13.2.3 for a description of support for OPTIONAL attributes).

Also, clients OPTIONALLY supply Job Template attributes in create

requests.

Job Template attributes conform to the following rules. For each Job

Template attribute called "xxx":

1. If the Printer object supports "xxx" then it MUST support both a

"xxx-default" attribute (unless there is a "No" in the table

below) and a "xxx-supported" attribute. If the Printer object

doesn't support "xxx", then it MUST support neither an "xxx-

default" attribute nor an "xxx-supported" attribute, and it MUST

treat an attribute "xxx" supplied by a client as unsupported.

An attribute "xxx" may be supported for some document formats

and not supported for other document formats. For example, it

is expected that a Printer object would only support

"orientation-requested" for some document formats (such as '

text/plain' or 'text/html') but not others (such as '

application/postscript').

2. "xxx" is OPTIONALLY supplied by the client in a create request.

If "xxx" is supplied, the client is indicating a desired job

processing behavior for this Job. When "xxx" is not supplied,

the client is indicating that the Printer object apply its

default job processing behavior at job processing time if the

document content does not contain an embedded instruction

indicating an xxx-related behavior.

Note: Since an administrator MAY change the default value

attribute after a Job object has been submitted but before it

has been processed, the default value used by the Printer object

at job processing time may be different that the default value

in effect at job submission time.

3. The "xxx-supported" attribute is a Printer object attribute that

describes which job processing behaviors are supported by that

Printer object. A client can query the Printer object to find

out what xxx-related behaviors are supported by inspecting the

returned values of the "xxx-supported" attribute.

Note: The "xxx" in each "xxx-supported" attribute name is

singular, even though an "xxx-supported" attribute usually has

more than one value, such as "job-sheet-supported", unless the

"xxx" Job Template attribute is plural, such as "finishings" or

"sides". In such cases the "xxx-supported" attribute names are:

"finishings-supported" and "sides-supported".

4. The "xxx-default" default value attribute describes what will be

done at job processing time when no other job processing

information is supplied by the client (either explicitly as an

IPP attribute in the create request or implicitly as an embedded

instruction within the document data).

If an application wishes to present an end user with a list of

supported values from which to choose, the application SHOULD query

the Printer object for its supported value attributes. The

application SHOULD also query the default value attributes. If the

application then limits selectable values to only those value that

are supported, the application can guarantee that the values supplied

by the client in the create request all fall within the set of

supported values at the Printer. When querying the Printer, the

client MAY enumerate each attribute by name in the Get-Printer-

Attributes Request, or the client MAY just name the "job-template"

group in order to get the complete set of supported attributes (both

supported and default attributes).

The "finishings" attribute is an example of a Job Template attribute.

It can take on a set of values such as 'staple', 'punch', and/or '

cover'. A client can query the Printer object for the "finishings-

supported" attribute and the "finishings-default" attribute. The

supported attribute contains a set of supported values. The default

value attribute contains the finishing value(s) that will be used for

a new Job if the client does not supply a "finishings" attribute in

the create request and the document data does not contain any

corresponding finishing instructions. If the client does supply the

"finishings" attribute in the create request, the IPP object

validates the value or values to make sure that they are a subset of

the supported values identified in the Printer object's "finishings-

supported" attribute. See section 3.2.1.2.

The table below summarizes the names and relationships for all Job

Template attributes. The first column of the table (labeled "Job

Attribute") shows the name and syntax for each Job Template attribute

in the Job object. These are the attributes that can optionally be

supplied by the client in a create request. The last two columns

(labeled "Printer: Default Value Attribute" and "Printer: Supported

Values Attribute") shows the name and syntax for each Job Template

attribute in the Printer object (the default value attribute and the

supported values attribute). A "No" in the table means the Printer

MUST NOT support the attribute (that is, the attribute is simply not

applicable). For brevity in the table, the 'text' and 'name' entries

do not show the maximum length for each attribute.

+===================+======================+======================+

Job Attribute Printer: Default Value Printer: Supported

Attribute Values Attribute

+===================+======================+======================+

job-priority job-priority-default job-priority-supported

(integer 1:100) (integer 1:100) (integer 1:100)

+-------------------+----------------------+----------------------+

job-hold-until job-hold-until- job-hold-until-

(type3 keyword default supported

name) (type3 keyword (1setOf

name) type3 keyword name)

+-------------------+----------------------+----------------------+

job-sheets job-sheets-default job-sheets-supported

(type3 keyword (type3 keyword (1setOf

name) name) type3 keyword name)

+-------------------+----------------------+----------------------+

multiple-document- multiple-document- multiple-document-

handling handling-default handling-supported

(type2 keyword) (type2 keyword) (1setOf type2 keyword)

+-------------------+----------------------+----------------------+

+===================+======================+======================+

Job Attribute Printer: Default Value Printer: Supported

Attribute Values Attribute

+===================+======================+======================+

copies copies-default copies-supported

(integer (1:MAX)) (integer (1:MAX)) (rangeOfInteger

(1:MAX))

+-------------------+----------------------+----------------------+

finishings finishings-default finishings-supported

(1setOf type2 enum)(1setOf type2 enum) (1setOf type2 enum)

+-------------------+----------------------+----------------------+

page-ranges No page-ranges-

(1setOf supported (boolean)

rangeOfInteger

(1:MAX))

+-------------------+----------------------+----------------------+

sides sides-default sides-supported

(type2 keyword) (type2 keyword) (1setOf type2 keyword)

+-------------------+----------------------+----------------------+

number-up number-up-default number-up-supported

(integer (1:MAX)) (integer (1:MAX)) (1setOf integer

(1:MAX)

rangeOfInteger

(1:MAX))

+-------------------+----------------------+----------------------+

orientation- orientation-requested-orientation-requested-

requested default supported

(type2 enum) (type2 enum) (1setOf type2 enum)

+-------------------+----------------------+----------------------+

media media-default media-supported

(type3 keyword (type3 keyword (1setOf

name) name) type3 keyword name)

media-ready

(1setOf

type3 keyword name)

+-------------------+----------------------+----------------------+

printer-resolution printer-resolution- printer-resolution-

(resolution) default supported

(resolution) (1setOf resolution)

+-------------------+----------------------+----------------------+

print-quality print-quality-default print-quality-

(type2 enum) (type2 enum) supported

(1setOf type2 enum)

+-------------------+----------------------+----------------------+

4.2.1 job-priority (integer(1:100))

This attribute specifies a priority for scheduling the Job. A higher

value specifies a higher priority. The value 1 indicates the lowest

possible priority. The value 100 indicates the highest possible

priority. Among those jobs that are ready to print, a Printer MUST

print all jobs with a priority value of n before printing those with

a priority value of n-1 for all n.

If the Printer object supports this attribute, it MUST always support

the full range from 1 to 100. No administrative restrictions are

permitted. This way an end-user can always make full use of the

entire range with any Printer object. If privileged jobs are

implemented outside IPP/1.0, they MUST have priorities higher than

100, rather than restricting the range available to end-users.

If the client does not supply this attribute and this attribute is

supported by the Printer object, the Printer object MUST use the

value of the Printer object's "job-priority-default" at job

submission time (unlike most Job Template attributes that are used if

necessary at job processing time).

The syntax for the "job-priority-supported" is also integer(1:100).

This single integer value indicates the number of priority levels

supported. The Printer object MUST take the value supplied by the

client and map it to the closest integer in a sequence of n integers

values that are evenly distributed over the range from 1 to 100 using

the formula:

roundToNearestInt((100x+50)/n)

where n is the value of "job-priority-supported" and x ranges from 0

through n-1.

For example, if n=1 the sequence of values is 50; if n=2, the

sequence of values is: 25 and 75; if n = 3, the sequence of values

is: 17, 50 and 83; if n = 10, the sequence of values is: 5, 15, 25,

35, 45, 55, 65, 75, 85, and 95; if n = 100, the sequence of values

is: 1, 2, 3, . 100.

If the value of the Printer object's "job-priority-supported" is 10

and the client supplies values in the range 1 to 10, the Printer

object maps them to 5, in the range 11 to 20, the Printer object maps

them to 15, etc.

4.2.2 job-hold-until (type3 keyword name (MAX))

This attribute specifies the named time period during which the Job

MUST become a candidate for printing.

Standard keyword values for named time periods are:

'no-hold': immediately, if there are not other reasons to hold the

job

'day-time': during the day

'evening': evening

'night': night

'weekend': weekend

'second-shift': second-shift (after close of business)

'third-shift': third-shift (after midnight)

An administrator MUST associate allowable print times with a named

time period (by means outside IPP/1.0). An administrator is

encouraged to pick names that suggest the type of time period. An

administrator MAY define additional values using the 'name' or '

keyword' attribute syntax, depending on implementation.

If the value of this attribute specifies a time period that is in the

future, the Printer MUST add the 'job-hold-until-specified' value to

the job's "job-state-reasons" attribute, move the job to the '

pending-held' state, and MUST NOT schedule the job for printing until

the specified time-period arrives. When the specified time period

arrives, the Printer MUST remove the 'job-hold-until-specified' value

from the job's "job-state-reason" attribute and, if there are no

other job state reasons that keep the job in the 'pending-held'

state, the Printer MUST consider the job as a candidate for

processing by moving the job to the 'pending' state.

If this job attribute value is the named value 'no-hold', or the

specified time period has already started, the job MUST be a

candidate for processing immediately.

If the client does not supply this attribute and this attribute is

supported by the Printer object, the Printer object MUST use the

value of the Printer object's "job-hold-until-default" at job

submission time (unlike most Job Template attributes that are used if

necessary at job processing time).

4.2.3 job-sheets (type3 keyword name(MAX))

This attribute determines which job start/end sheet(s), if any, MUST

be printed with a job.

Standard keyword values are:

'none': no job sheet is printed

'standard': one or more site specific standard job sheets are

printed, e.g. a single start sheet or both start and end sheet

is printed

An administrator MAY define additional values using the 'name' or '

keyword' attribute syntax, depending on implementation.

Note: The effect of this attribute on jobs with multiple documents

MAY be affected by the "multiple-document-handling" job attribute

(section 4.2.4), depending on the job sheet semantics.

4.2.4 multiple-document-handling (type2 keyword)

This attribute is relevant only if a job consists of two or more

documents. The attribute controls finishing operations and the

placement of one or more print-stream pages into impressions and onto

media sheets. When the value of the "copies" attribute exceeds 1, it

also controls the order in which the copies that result from

processing the documents are produced. For the purposes of this

explanations, if "a" represents an instance of document data, then

the result of processing the data in document "a" is a sequence of

media sheets represented by "a(*)".

Standard keyword values are:

'single-document': If a Job object has multiple documents, say, the

document data is called a and b, then the result of processing

all the document data (a and then b) MUST be treated as a single

sequence of media sheets for finishing operations; that is,

finishing would be performed on the concatenation of the

sequences a(*),b(*). The Printer object MUST NOT force the data

in each document instance to be formatted onto a new print-

stream page, nor to start a new impression on a new media sheet.

If more than one copy is made, the ordering of the sets of media

sheets resulting from processing the document data MUST be a(*),

b(*), a(*), b(*), ..., and the Printer object MUST force each

copy (a(*),b(*)) to start on a new media sheet.

'separate-documents-uncollated-copies': If a Job object has

multiple documents, say, the document data is called a and b,

then the result of processing the data in each document instance

MUST be treated as a single sequence of media sheets for

finishing operations; that is, the sets a(*) and b(*) would each

be finished separately. The Printer object MUST force each copy

of the result of processing the data in a single document to

start on a new media sheet. If more than one copy is made, the

ordering of the sets of media sheets resulting from processing

the document data MUST be a(*), a(*), ..., b(*), b(*) ... .

'separate-documents-collated-copies': If a Job object has multiple

documents, say, the document data is called a and b, then the

result of processing the data in each document instance MUST be

treated as a single sequence of media sheets for finishing

operations; that is, the sets a(*) and b(*) would each be

finished separately. The Printer object MUST force each copy of

the result of processing the data in a single document to start

on a new media sheet. If more than one copy is made, the

ordering of the sets of media sheets resulting from processing

the document data MUST be a(*), b(*), a(*), b(*), ... .

'single-document-new-sheet': Same as 'single-document', except

that the Printer object MUST ensure that the first impression of

each document instance in the job is placed on a new media

sheet. This value allows multiple documents to be stapled

together with a single staple where each document starts on a

new sheet.

The 'single-document' value is the same as 'separate-documents-

collated-copies' with respect to ordering of print-stream pages, but

not media sheet generation, since 'single-document' will put the

first page of the next document on the back side of a sheet if an odd

number of pages have been produced so far for the job, while '

separate-documents-collated-copies' always forces the next document

or document copy on to a new sheet. In addition, if the "finishings"

attribute specifies 'staple', then with 'single-document', documents

a and b are stapled together as a single document with no regard to

new sheets, with 'single-document-new-sheet', documents a and b are

stapled together as a single document, but document b starts on a new

sheet, but with 'separate-documents-uncollated-copies' and '

separate-documents-collated-copies', documents a and b are stapled

separately.

Note: None of these values provide means to produce uncollated sheets

within a document, i.e., where multiple copies of sheet n are

produced before sheet n+1 of the same document.

The relationship of this attribute and the other attributes that

control document processing is described in section 15.3.

4.2.5 copies (integer(1:MAX))

This attribute specifies the number of copies to be printed.

On many devices the supported number of collated copies will be

limited by the number of physical output bins on the device, and may

be different from the number of uncollated copies which can be

supported.

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

4.2.6 finishings (1setOf type2 enum)

This attribute identifies the finishing operations that the Printer

uses for each copy of each printed document in the Job. For Jobs with

multiple documents, the "multiple-document-handling" attribute

determines what constitutes a "copy" for purposes of finishing.

Standard enum values are:

Value Symbolic Name and Description

'3' 'none': Perform no finishing

'4' 'staple': Bind the document(s) with one or more staples.

The exact number and placement of the staples is

site-defined.

'5' 'punch': This value indicates that holes are required in

the finished document. The exact number and placement

of the holes is site-defined The punch specification

MAY be satisfied (in a site- and implementation-

specific manner) either by drilling/punching, or by

substituting pre-drilled media.

'6' 'cover': This value is specified when it is desired to

select a non-printed (or pre-printed) cover for the

document. This does not supplant the specification of

a printed cover (on cover stock medium) by the

document itself.

'7' 'bind': This value indicates that a binding is to be

applied to the document; the type and placement of the

binding is site-defined."

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

If the client supplies a value of 'none' along with any other

combination of values, it is the same as if only that other

combination of values had been supplied (that is the 'none' value has

no effect).

4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX))

This attribute identifies the range(s) of print-stream pages that the

Printer object uses for each copy of each document which are to be

printed. Nothing is printed for any pages identified that do not

exist in the document(s). Ranges MUST be in ascending order, for

example: 1-3, 5-7, 15-19 and MUST NOT overlap, so that a non-spooling

Printer object can process the job in a single pass. If the ranges

are not ascending or are overlapping, the IPP object MUST reject the

request and return the 'client-error-bad-request' status code. The

attribute is associated with print-stream pages not application-

numbered pages (for example, the page numbers found in the headers

and or footers for certain word processing applications).

For Jobs with multiple documents, the "multiple-document-handling"

attribute determines what constitutes a "copy" for purposes of the

specified page range(s). When "multiple-document-handling" is '

single-document', the Printer object MUST apply each supplied page

range once to the concatenation of the print-stream pages. For

example, if there are 8 documents of 10 pages each, the page-range '

41:60' prints the pages in the 5th and 6th documents as a single

document and none of the pages of the other documents are printed.

When "multiple-document-handling" is 'separate-documents-uncollated-

copies' or 'separate-documents-collated-copies', the Printer object

MUST apply each supplied page range repeatedly to each document copy.

For the same job, the page-range '1:3, 10:10' would print the first 3

pages and the 10th page of each of the 8 documents in the Job, as 8

separate documents.

In most cases, the exact pages to be printed will be generated by a

device driver and this attribute would not be required. However,

when printing an archived document which has already been formatted,

the end user may elect to print just a subset of the pages contained

in the document. In this case, if page-range = n.m is specified, the

first page to be printed will be page n. All subsequent pages of the

document will be printed through and including page m.

"page-ranges-supported" is a boolean value indicating whether or not

the printer is capable of supporting the printing of page ranges.

This capability may differ from one PDL to another. There is no

"page-ranges-default" attribute. If the "page-ranges" attribute is

not supplied by the client, all pages of the document will be

printed.

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

4.2.8 sides (type2 keyword)

This attribute specifies how print-stream pages are to be imposed

upon the sides of an instance of a selected medium, i.e., an

impression.

The standard keyword values are:

'one-sided': imposes each consecutive print-stream page upon the

same side of consecutive media sheets.

'two-sided-long-edge': imposes each consecutive pair of print-

stream pages upon front and back sides of consecutive media

sheets, such that the orientation of each pair of print-stream

pages on the medium would be correct for the reader as if for

binding on the long edge. This imposition is sometimes called '

duplex' or 'head-to-head'.

'two-sided-short-edge': imposes each consecutive pair of print-

stream pages upon front and back sides of consecutive media

sheets, such that the orientation of each pair of print-stream

pages on the medium would be correct for the reader as if for

binding on the short edge. This imposition is sometimes called

'tumble' or 'head-to-toe'.

'two-sided-long-edge', 'two-sided-short-edge', 'tumble', and 'duplex'

all work the same for portrait or landscape. However 'head-to-toe'

is 'tumble' in portrait but 'duplex' in landscape. 'head-to-head'

also switches between 'duplex' and 'tumble' when using portrait and

landscape modes.

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

4.2.9 number-up (integer(1:MAX))

This attribute specifies the number of print-stream pages to impose

upon a single side of an instance of a selected medium. For example,

if the value is:

Value Description

'1' the Printer MUST place one print-stream page on a single

side of an instance of the selected medium (MAY add

some sort of translation, scaling, or rotation).

'2' the Printer MUST place two print-stream pages on a single

side of an instance of the selected medium (MAY add

some sort of translation, scaling, or rotation).

'4' the Printer MUST place four print-stream pages on a single

side of an instance of the selected medium (MAY add

some sort of translation, scaling, or rotation).

This attribute primarily controls the translation, scaling and

rotation of print-stream pages.

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

4.2.10 orientation-requested (type2 enum)

This attribute indicates the desired orientation for printed print-

stream pages; it does not describe the orientation of the client-

supplied print-stream pages.

For some document formats (such as 'application/postscript'), the

desired orientation of the print-stream pages is specified within the

document data. This information is generated by a device driver

prior to the submission of the print job. Other document formats

(such as 'text/plain') do not include the notion of desired

orientation within the document data. In the latter case it is

possible for the Printer object to bind the desired orientation to

the document data after it has been submitted. It is expected that a

Printer object would only support "orientations-requested" for some

document formats (e.g., 'text/plain' or 'text/html') but not others

(e.g., 'application/postscript'). This is no different than any

other Job Template attribute since section 4.2, item 1, points out

that a Printer object may support or not support any Job Template

attribute based on the document format supplied by the client.

However, a special mention is made here since it is very likely that

a Printer object will support "orientation-requested" for only a

subset of the supported document formats.

Standard enum values are:

Value Symbolic Name and Description

'3' 'portrait': The content will be imaged across the short

edge of the medium.

'4' 'landscape': The content will be imaged across the long

edge of the medium. Landscape is defined to be a

rotation of the print-stream page to be imaged by +90

degrees with respect to the medium (i.e. anti-

clockwise) from the portrait orientation. Note: The

+90 direction was chosen because simple finishing on

the long edge is the same edge whether portrait or

landscape

'5' 'reverse-landscape': The content will be imaged across the

long edge of the medium. Reverse-landscape is defined

to be a rotation of the print-stream page to be imaged

by - 90 degrees with respect to the medium (i.e.

clockwise) from the portrait orientation. Note: The '

reverse-landscape' value was added because some

applications rotate landscape -90 degrees from

portrait, rather than +90 degrees.

'6' 'reverse-portrait': The content will be imaged across the

short edge of the medium. Reverse-portrait is defined

to be a rotation of the print-stream page to be imaged

by 180 degrees with respect to the medium from the

portrait orientation. Note: The 'reverse-portrait'

value was added for use with the "finishings"

attribute in cases where the opposite edge is desired

for finishing a portrait document on simple finishing

devices that have only one finishing position. Thus a

'text'/plain' portrait document can be stapled "on the

right" by a simple finishing device as is common use

with some middle eastern languages such as Hebrew.

Note: The effect of this attribute on jobs with multiple documents is

controlled by the "multiple-document-handling" job attribute (section

4.2.4) and the relationship of this attribute and the other

attributes that control document processing is described in section

15.3.

4.2.11 media (type3 keyword name(MAX))

This attribute identifies the medium that the Printer uses for all

impressions of the Job.

The values for "media" include medium-names, medium-sizes, input-

trays and electronic forms so that one attribute specifies the media.

If a Printer object supports a medium name as a value of this

attribute, such a medium name implicitly selects an input-tray that

contains the specified medium. If a Printer object supports a medium

size as a value of this attribute, such a medium size implicitly

selects a medium name that in turn implicitly selects an input-tray

that contains the medium with the specified size. If a Printer

object supports an input-tray as the value of this attribute, such an

input-tray implicitly selects the medium that is in that input-tray

at the time the job prints. This case includes manual-feed input-

trays. If a Printer object supports an electronic form as the value

of this attribute, such an electronic form implicitly selects a

medium-name that in turn implicitly selects an input-tray that

contains the medium specified by the electronic form. The electronic

form also implicitly selects an image that the Printer MUST merge

with the document data as its prints each page.

Standard keyword values are (taken from ISO DPA and the Printer MIB)

and are listed in section 14. An administrator MAY define additional

values using the 'name' or 'keyword' attribute syntax, depending on

implementation.

There is also an additional Printer attribute named "media-ready"

which differs from "media-supported" in that legal values only

include the subset of "media-supported" values that are physically

loaded and ready for printing with no operator intervention required.

If an IPP object supports "media-supported", it NEED NOT support

"media-ready".

The relationship of this attribute and the other attributes that

control document processing is described in section 15.3.

4.2.12 printer-resolution (resolution)

This attribute identifies the resolution that Printer uses for the

Job.

4.2.13 print-quality (type2 enum)

This attribute specifies the print quality that the Printer uses for

the Job.

The standard enum values are:

Value Symbolic Name and Description

'3' 'draft': lowest quality available on the printer

'4' 'normal': normal or intermediate quality on the printer

'5' 'high': highest quality available on the printer

4.3 Job Description Attributes

The attributes in this section form the attribute group called "job-

description". The following table summarizes these attributes. The

third column indicates whether the attribute is a REQUIRED attribute

that MUST be supported by Printer objects. If it is not indicated as

REQUIRED, then it is OPTIONAL. The maximum size in octets for 'text'

and 'name' attributes is indicated in parenthesizes.

+----------------------------+----------------------+----------------+

Attribute Syntax REQUIRED?

+----------------------------+----------------------+----------------+

job-uri uri REQUIRED

+----------------------------+----------------------+----------------+

job-id integer(1:MAX) REQUIRED

+----------------------------+----------------------+----------------+

job-printer-uri uri REQUIRED

+----------------------------+----------------------+----------------+

job-more-info uri

+----------------------------+----------------------+----------------+

job-name name (MAX) REQUIRED

+----------------------------+----------------------+----------------+

job-originating-user-name name (MAX) REQUIRED

+----------------------------+----------------------+----------------+

job-state type1 enum REQUIRED

+----------------------------+----------------------+----------------+

job-state-reasons 1setOf type2 keyword

+----------------------------+----------------------+----------------+

job-state-message text (MAX)

+----------------------------+----------------------+----------------+

number-of-documents integer (0:MAX)

+----------------------------+----------------------+----------------+

output-device-assigned name (127)

+----------------------------+----------------------+----------------+

time-at-creation integer (0:MAX)

+----------------------------+----------------------+----------------+

time-at-processing integer (0:MAX)

+----------------------------+----------------------+----------------+

time-at-completed integer (0:MAX)

+----------------------------+----------------------+----------------+

number-of-intervening-jobs integer (0:MAX)

+----------------------------+----------------------+----------------+

job-message-from-operator text (127)

+----------------------------+----------------------+----------------+

job-k-octets integer (0:MAX)

+----------------------------+----------------------+----------------+

job-impressions integer (0:MAX)

+----------------------------+----------------------+----------------+

+----------------------------+----------------------+----------------+

Attribute Syntax REQUIRED?

+----------------------------+----------------------+----------------+

job-media-sheets integer (0:MAX)

+----------------------------+----------------------+----------------+

job-k-octets-processed integer (0:MAX)

+----------------------------+----------------------+----------------+

job-impressions-completed integer (0:MAX)

+----------------------------+----------------------+----------------+

job-media-sheets-completed integer (0:MAX)

+----------------------------+----------------------+----------------+

attributes-charset charset REQUIRED

+----------------------------+----------------------+----------------+

attributes-natural-language naturalLanguage REQUIRED

+----------------------------+----------------------+----------------+

4.3.1 job-uri (uri)

This REQUIRED attribute contains the URI for the job. The Printer

object, on receipt of a new job, generates a URI which identifies the

new Job. The Printer object returns the value of the "job-uri"

attribute as part of the response to a create request. The precise

format of a Job URI is implementation dependent. If the Printer

object supports more than one URI and there is some relationship

between the newly formed Job URI and the Printer object's URI, the

Printer object uses the Printer URI supplied by the client in the

create request. For example, if the create request comes in over a

secure channel, the new Job URI MUST use the same secure channel.

This can be guaranteed because the Printer object is responsible for

generating the Job URI and the Printer object is aware of its

security configuration and policy as well as the Printer URI used in

the create request.

For a description of this attribute and its relationship to "job-id"

and "job-printer-uri" attribute, see the discussion in section 2.4 on

"Object Identity".

4.3.2 job-id (integer(1:MAX))

This REQUIRED attribute contains the ID of the job. The Printer, on

receipt of a new job, generates an ID which identifies the new Job on

that Printer. The Printer returns the value of the "job-id"

attribute as part of the response to a create request. The 0 value

is not included to allow for compatibility with SNMP index values

which also cannot be 0.

For a description of this attribute and its relationship to "job-uri"

and "job-printer-uri" attribute, see the discussion in section 2.4 on

"Object Identity".

4.3.3 job-printer-uri (uri)

This REQUIRED attribute identifies the Printer object that created

this Job object. When a Printer object creates a Job object, it

populates this attribute with the Printer object URI that was used in

the create request. This attribute permits a client to identify the

Printer object that created this Job object when only the Job

object's URI is available to the client. The client queries the

creating Printer object to determine which languages, charsets,

operations, are supported for this Job.

For a description of this attribute and its relationship to "job-uri"

and "job-id" attribute, see the discussion in section 2.4 on "Object

Identity".

4.3.4 job-more-info (uri)

Similar to "printer-more-info", this attribute contains the URI

referencing some resource with more information about this Job

object, perhaps an HTML page containing information about the Job.

4.3.5 job-name (name(MAX))

This REQUIRED attribute is the name of the job. It is a name that is

more user friendly than the "job-uri" attribute value. It does not

need to be unique between Jobs. The Job's "job-name" attribute is

set to the value supplied by the client in the "job-name" operation

attribute in the create request (see Section 3.2.1.1). If, however,

the "job-name" operation attribute is not supplied by the client in

the create request, the Printer object, on creation of the Job, MUST

generate a name. The printer SHOULD generate the value of the Job's

"job-name" attribute from the first of the following sources that

produces a value: 1) the "document-name" operation attribute of the

first (or only) document, 2) the "document-URI" attribute of the

first (or only) document, or 3) any other piece of Job specific

and/or Document Content information.

4.3.6 job-originating-user-name (name(MAX))

This REQUIRED attribute contains the name of the end user that

submitted the print job. The Printer object sets this attribute to

the most authenticated printable name that it can obtain from the

authentication service over which the IPP operation was received.

Only if such is not available, does the Printer object use the value

supplied by the client in the "requesting-user-name" operation

attribute of the create operation (see Section 8).

Note: The Printer object needs to keep an internal originating user

id of some form, typically as a credential of a principal, with the

Job object. Since such an internal attribute is implementation-

dependent and not of interest to clients, it is not specified as a

Job Description attribute. This originating user id is used for

authorization checks (if any) on all subsequent operation.

4.3.7 job-state (type1 enum)

This REQUIRED attribute identifies the current state of the job.

Even though the IPP protocol defines eight values for job states,

implementations only need to support those states which are

appropriate for the particular implementation. In other words, a

Printer supports only those job states implemented by the output

device and available to the Printer object implementation.

Standard enum values are:

Values Symbolic Name and Description

'3' 'pending': The job is a candidate to start processing, but

is not yet processing.

'4' 'pending-held': The job is not a candidate for processing

for any number of reasons but will return to the '

pending' state as soon as the reasons are no longer

present. The job's "job-state-reason" attribute MUST

indicate why the job is no longer a candidate for

processing.

'5' 'processing': One or more of:

1. the job is using, or is attempting to use, one or

more purely software processes that are analyzing,

creating, or interpreting a PDL, etc.,

2. the job is using, or is attempting to use, one or

more hardware devices that are interpreting a PDL,

making marks on a medium, and/or performing finishing,

such as stapling, etc.,

3. the Printer object has made the job ready for

printing, but the output device is not yet printing

it, either because the job hasn't reached the output

device or because the job is queued in the output

device or some other spooler, awaiting the output

device to print it.

When the job is in the 'processing' state, the entire

job state includes the detailed status represented in

the printer's "printer-state", "printer-state-

reasons", and "printer-state-message" attributes.

Implementations MAY, though they NEED NOT, include

additional values in the job's "job-state-reasons"

attribute to indicate the progress of the job, such as

adding the 'job-printing' value to indicate when the

output device is actually making marks on paper and/or

the 'processing-to-stop-point' value to indicate that

the IPP object is in the process of canceling or

aborting the job. Most implementations won't bother

with this nuance.

'6' 'processing-stopped': The job has stopped while processing

for any number of reasons and will return to the '

processing' state as soon as the reasons are no longer

present.

The job's "job-state-reason" attribute MAY indicate

why the job has stopped processing. For example, if

the output device is stopped, the 'printer-stopped'

value MAY be included in the job's "job-state-reasons"

attribute.

Note: When an output device is stopped, the device

usually indicates its condition in human readable form

locally at the device. A client can obtain more

complete device status remotely by querying the

Printer object's "printer-state", "printer-state-

reasons" and "printer-state-message" attributes.

'7' 'canceled': The job has been canceled by a Cancel-Job

operation and the Printer object has completed

canceling the job and all job status attributes have

reached their final values for the job. While the

Printer object is canceling the job, the job remains

in its current state, but the job's "job-state-

reasons" attribute SHOULD contain the 'processing-to-

stop-point' value and one of the 'canceled-by-user', '

canceled-by-operator', or 'canceled-at-device' value.

When the job moves to the 'canceled' state, the '

processing-to-stop-point' value, if present, MUST be

removed, but the 'canceled-by-xxx', if present, MUST

remain.

'8' 'aborted': The job has been aborted by the system, usually

while the job was in the 'processing' or 'processing-

stopped' state and the Printer has completed aborting

the job and all job status attributes have reached

their final values for the job. While the Printer

object is aborting the job, the job remains in its

current state, but the job's "job-state-reasons"

attribute SHOULD contain the 'processing-to-stop-

point' and 'aborted-by-system' values. When the job

moves to the 'aborted' state, the 'processing-to-

stop-point' value, if present, MUST be removed, but

the 'aborted-by-system' value, if present, MUST

remain.

'9' 'completed': The job has completed successfully or with

warnings or errors after processing and all of the job

media sheets have been successfully stacked in the

appropriate output bin(s) and all job status

attributes have reached their final values for the

job. The job's "job-state-reasons" attribute SHOULD

contain one of: 'completed-successfully', '

completed-with-warnings', or 'completed-with-errors'

values.

The final value for this attribute MUST be one of: 'completed', '

canceled', or 'aborted' before the Printer removes the job

altogether. The length of time that jobs remain in the 'canceled', '

aborted', and 'completed' states depends on implementation.

The following figure shows the normal job state transitions.

+----> canceled

/

+----> pending --------> processing ---------+------> completed

^ ^ --->+ +----> aborted

v v /

+----> pending-held processing-stopped ---+

Normally a job progresses from left to right. Other state

transitions are unlikely, but are not forbidden. Not shown are the

transitions to the 'canceled' state from the 'pending', 'pending-

held', and 'processing-stopped' states.

Jobs reach one of the three terminal states: 'completed', 'canceled',

or 'aborted', after the jobs have completed all activity, including

stacking output media, after the jobs have completed all activity,

and all job status attributes have reached their final values for the

job.

Note: As with all other IPP attributes, if the implementation can not

determine the correct value for this attribute, it SHOULD respond

with the out-of-band value 'unknown' (see section 4.1) rather than

try to guess at some possibly incorrect value and give the end user

the wrong impression about the state of the Job object. For example,

if the implementation is just a gateway into some printing system

that does not provide detailed status about the print job, the IPP

Job object's state might literally be 'unknown'.

4.3.8 job-state-reasons (1setOf type2 keyword)

This attribute provides additional information about the job's

current state, i.e., information that augments the value of the job's

"job-state" attribute.

Implementation of these values is OPTIONAL, i.e., a Printer NEED NOT

implement them, even if (1) the output device supports the

functionality represented by the reason and (2) is available to the

Printer object implementation. These values MAY be used with any job

state or states for which the reason makes sense. Furthermore, when

implemented, the Printer MUST return these values when the reason

applies and MUST NOT return them when the reason no longer applies

whether the value of the Job's "job-state" attribute changed or not.

When the Job does not have any reasons for being in its current

state, the value of the Job's "job-state-reasons" attribute MUST be '

none'.

Note: While values cannot be added to the 'job-state' attribute

without impacting deployed clients that take actions upon receiving

"job-state" values, it is the intent that additional "job-state-

reasons" values can be defined and registered without impacting such

deployed clients. In other words, the "job-state-reasons" attribute

is intended to be extensible.

The following standard keyword values are defined. For ease of

understanding, the values are presented in the order in which the

reasons are likely to occur (if implemented), starting with the '

job-incoming' value:

'none': There are no reasons for the job's current state.

'job-incoming': The Create-Job operation has been accepted by the

Printer, but the Printer is expecting additional Send-Document

and/or Send-URI operations and/or is accessing/accepting

document data.

'submission-interrupted': The job was not completely submitted for

some unforeseen reason, such as: (1) the Printer has crashed

before the job was closed by the client, (2) the Printer or the

document transfer method has crashed in some non-recoverable way

before the document data was entirely transferred to the

Printer, (3) the client crashed or failed to close the job

before the time-out period. See section 4.4.28.

'job-outgoing': The Printer is transmitting the job to the output

device.

'job-hold-until-specified': The value of the job's "job-hold-

until" attribute was specified with a time period that is still

in the future. The job MUST NOT be a candidate for processing

until this reason is removed and there are no other reasons to

hold the job.

'resources-are-not-ready': At least one of the resources needed by

the job, such as media, fonts, resource objects, etc., is not

ready on any of the physical printer's for which the job is a

candidate. This condition MAY be detected when the job is

accepted, or subsequently while the job is pending or

processing, depending on implementation. The job may remain in

its current state or be moved to the 'pending-held' state,

depending on implementation and/or job scheduling policy.

'printer-stopped-partly': The value of the Printer's "printer-

state-reasons" attribute contains the value 'stopped-partly'.

'printer-stopped': The value of the Printer's "printer-state"

attribute is 'stopped'.

'job-interpreting': Job is in the 'processing' state, but more

specifically, the Printer is interpreting the document data.

'job-queued': Job is in the 'processing' state, but more

specifically, the Printer has queued the document data.

'job-transforming': Job is in the 'processing' state, but more

specifically, the Printer is interpreting document data and

producing another electronic representation.

'job-printing': The output device is marking media. This value is

useful for Printers which spend a great deal of time processing

(1) when no marking is happening and then want to show that

marking is now happening or (2) when the job is in the process

of being canceled or aborted while the job remains in the '

processing' state, but the marking has not yet stopped so that

impression or sheet counts are still increasing for the job.

'job-canceled-by-user': The job was canceled by the owner of the

job using the Cancel-Job request, i.e., by a user whose

authenticated identity is the same as the value of the

originating user that created the Job object, or by some other

authorized end-user, such as a member of the job owner's

security group.

'job-canceled-by-operator': The job was canceled by the operator

using the Cancel-Job request, i.e., by a user who has been

authenticated as having operator privileges (whether local or

remote). If the security policy is to allow anyone to cancel

anyone's job, then this value may be used when the job is

canceled by other than the owner of the job. For such a

security policy, in effect, everyone is an operator as far as

canceling jobs with IPP is concerned.

'job-canceled-at-device': The job was canceled by an unidentified

local user, i.e., a user at a console at the device.

'aborted-by-system': The job (1) is in the process of being

aborted, (2) has been aborted by the system and placed in the '

aborted' state, or (3) has been aborted by the system and placed

in the 'pending-held' state, so that a user or operator can

manually try the job again.

'processing-to-stop-point': The requester has issued a Cancel-Job

operation or the Printer object has aborted the job, but is

still performing some actions on the job until a specified stop

point occurs or job termination/cleanup is completed.

This reason is recommended to be used in conjunction with the '

processing' job state to indicate that the Printer object is

still performing some actions on the job while the job remains

in the 'processing' state. After all the job's job description

attributes have stopped incrementing, the Printer object moves

the job from the 'processing' state to the 'canceled' or '

aborted' job states.

'service-off-line': The Printer is off-line and accepting no jobs.

All 'pending' jobs are put into the 'pending-held' state. This

situation could be true if the service's or document transform's

input is impaired or broken.

'job-completed-successfully': The job completed successfully.

'job-completed-with-warnings': The job completed with warnings.

'job-completed-with-errors': The job completed with errors (and

possibly warnings too).

4.3.9 job-state-message (text(MAX))

This attribute specifies information about the "job-state" and "job-

state-reasons" attributes in human readable text. If the Printer

object supports this attribute, the Printer object MUST be able to

generate this message in any of the natural languages identified by

the Printer's "generated-natural-language-supported" attribute (see

the "attributes-natural-language" operation attribute specified in

Section 3.1.4.1).

Note: the value SHOULD NOT contain additional information not

contained in the values of the "job-state" and "job-states-reasons"

attributes, such as interpreter error information. Otherwise,

application programs might attempt to parse the (localized text).

For such additional information such as interpreter errors for

application program consumption, a new attribute with keyword values,

needs to be developed and registered.

4.3.10 number-of-documents (integer(0:MAX))

This attribute indicates the number of documents in the job, i.e.,

the number of Send-Document, Send-URI, Print-Job, or Print-URI

operations that the Printer has accepted for this job, regardless of

whether the document data has reached the Printer object or not.

Implementations supporting the OPTIONAL Create-Job/Send-

Document/Send-URI operations SHOULD support this attribute so that

clients can query the number of documents in each job.

4.3.11 output-device-assigned (name(127))

This attribute identifies the output device to which the Printer

object has assigned this job. If an output device implements an

embedded Printer object, the Printer object NEED NOT set this

attribute. If a print server implements a Printer object, the value

MAY be empty (zero-length string) or not returned until the Printer

object assigns an output device to the job. This attribute is

particularly useful when a single Printer object support multiple

devices (so called "fan-out").

4.3.12 time-at-creation (integer(0:MAX))

This attribute indicates the point in time at which the Job object

was created. In order to populate this attribute, the Printer object

uses the value in its "printer-up-time" attribute at the time the Job

object is created.

4.3.13 time-at-processing (integer(0:MAX))

This attribute indicates the point in time at which the Job object

began processing. In order to populate this attribute, the Printer

object uses the value in its "printer-up-time" attribute at the time

the Job object is moved into the 'processing' state for the first

time.

4.3.14 time-at-completed (integer(0:MAX))

This attribute indicates the point in time at which the Job object

completed (or was cancelled or aborted). In order to populate this

attribute, the Printer object uses the value in its "printer-up-time"

attribute at the time the Job object is moved into the 'completed' or

'canceled' or 'aborted' state.

4.3.15 number-of-intervening-jobs (integer(0:MAX))

This attribute indicates the number of jobs that are "ahead" of this

job in the relative chronological order of expected time to complete

(i.e., the current scheduled order). For efficiency, it is only

necessary to calculate this value when an operation is performed that

requests this attribute.

4.3.16 job-message-from-operator (text(127))

This attribute provides a message from an operator, system

administrator or "intelligent" process to indicate to the end user

the reasons for modification or other management action taken on a

job.

4.3.17 job-k-octets (integer(0:MAX))

This attribute specifies the total size of the document(s) in K

octets, i.e., in units of 1024 octets requested to be processed in

the job. The value MUST be rounded up, so that a job between 1 and

1024 octets MUST be indicated as being 1, 1025 to 2048 MUST be 2,

etc.

This value MUST NOT include the multiplicative factors contributed by

the number of copies specified by the "copies" attribute, independent

of whether the device can process multiple copies without making

multiple passes over the job or document data and independent of

whether the output is collated or not. Thus the value is independent

of the implementation and indicates the size of the document(s)

measured in K octets independent of the number of copies.

This value MUST also not include the multiplicative factor due to a

copies instruction embedded in the document data. If the document

data actually includes replications of the document data, this value

will include such replication. In other words, this value is always

the size of the source document data, rather than a measure of the

hardcopy output to be produced.

Note: This attribute and the following two attributes ("job-

impressions" and "job-media-sheets") are not intended to be counters;

they are intended to be useful routing and scheduling information if

known. For these three attributes, the Printer object may try to

compute the value if it is not supplied in the create request. Even

if the client does supply a value for these three attributes in the

create request, the Printer object MAY choose to change the value if

the Printer object is able to compute a value which is more accurate

than the client supplied value. The Printer object may be able to

determine the correct value for these three attributes either right

at job submission time or at any later point in time.

4.3.18 job-impressions (integer(0:MAX))

This attribute specifies the total size in number of impressions of

the document(s) being submitted (see the definition of impression in

section 13.2.5).

As with "job-k-octets", this value MUST NOT include the

multiplicative factors contributed by the number of copies specified

by the "copies" attribute, independent of whether the device can

process multiple copies without making multiple passes over the job

or document data and independent of whether the output is collated or

not. Thus the value is independent of the implementation and

reflects the size of the document(s) measured in impressions

independent of the number of copies.

As with "job-k-octets", this value MUST also not include the

multiplicative factor due to a copies instruction embedded in the

document data. If the document data actually includes replications

of the document data, this value will include such replication. In

other words, this value is always the number of impressions in the

source document data, rather than a measure of the number of

impressions to be produced by the job.

See the Note in the "job-k-octets" attribute that also applies to

this attribute.

4.3.19 job-media-sheets (integer(0:MAX))

This attribute specifies the total number of media sheets to be

produced for this job.

Unlike the "job-k-octets" and the "job-impressions" attributes, this

value MUST include the multiplicative factors contributed by the

number of copies specified by the "copies" attribute and a 'number of

copies' instruction embedded in the document data, if any. This

difference allows the system administrator to control the lower and

upper bounds of both (1) the size of the document(s) with "job-k-

octets-supported" and "job-impressions-supported" and (2) the size of

the job with "job-media-sheets-supported".

See the Note in the "job-k-octets" attribute that also applies to

this attribute.

4.3.20 job-k-octets-processed (integer(0:MAX))

This attribute specifies the total number of octets processed in K

octets, i.e., in units of 1024 octets so far. The value MUST be

rounded up, so that a job between 1 and 1024 octets inclusive MUST be

indicated as being 1, 1025 to 2048 inclusive MUST be 2, etc.

For implementations where multiple copies are produced by the

interpreter with only a single pass over the data, the final value

MUST be equal to the value of the "job-k-octets" attribute. For

implementations where multiple copies are produced by the interpreter

by processing the data for each copy, the final value MUST be a

multiple of the value of the "job-k-octets" attribute.

Note: This attribute and the following two attributes ("job-

impressions-completed" and "job-sheets-completed") are intended to be

counters. That is, the value for a job that has not started

processing MUST be 0. When the job's "job-state" is 'processing' or

'processing-stopped', this value is intended to contain the amount of

the job that has been processed to the time at which the attributes

are requested.

4.3.21 job-impressions-completed (integer(0:MAX))

This job attribute specifies the number of impressions completed for

the job so far. For printing devices, the impressions completed

includes interpreting, marking, and stacking the output.

See the note in "job-k-octets-processed" which also applies to this

attribute.

4.3.22 job-media-sheets-completed (integer(0:MAX))

This job attribute specifies the media-sheets completed marking and

stacking for the entire job so far whether those sheets have been

processed on one side or on both.

See the note in "job-k-octets-processed" which also applies to this

attribute.

4.3.23 attributes-charset (charset)

This REQUIRED attribute is populated using the value in the client

supplied "attributes-charset" attribute in the create request. It

identifies the charset (coded character set and encoding method) used

by any Job attributes with attribute syntax 'text' and 'name' that

were supplied by the client in the create request. See Section 3.1.4

for a complete description of the "attributes-charset" operation

attribute.

This attribute does not indicate the charset in which the 'text' and

'name' values are stored internally in the Job object. The internal

charset is implementation-defined. The IPP object MUST convert from

whatever the internal charset is to that being requested in an

operation as specified in Section 3.1.4.

4.3.24 attributes-natural-language (naturalLanguage)

This REQUIRED attribute is populated using the value in the client

supplied "attributes-natural-language" attribute in the create

request. It identifies the natural language used for any Job

attributes with attribute syntax 'text' and 'name' that were supplied

by the client in the create request. See Section 3.1.4 for a

complete description of the "attributes-natural-language" operation

attribute. See Sections 4.1.1.2 and 4.1.2.2 for how a Natural

Language Override may be supplied explicitly for each 'text' and '

name' attribute value that differs from the value identified by the

"attributes-natural-language" attribute.

4.4 Printer Description Attributes

These attributes form the attribute group called "printer-

description". The following table summarizes these attributes, their

syntax, and whether or not they are REQUIRED for a Printer object to

support. If they are not indicated as REQUIRED, they are OPTIONAL.

The maximum size in octets for 'text' and 'name' attributes is

indicated in parenthesizes.

Note: How these attributes are set by an Administrator is outside the

scope of this specification.

+----------------------------+----------------------+----------------+

Attribute Syntax REQUIRED?

+----------------------------+----------------------+----------------+

printer-uri-supported 1setOf uri REQUIRED

+----------------------------+----------------------+----------------+

uri-security-supported 1setOf type2 keyword REQUIRED

+----------------------------+----------------------+----------------+

printer-name name (127) REQUIRED

+----------------------------+----------------------+----------------+

printer-location text (127)

+----------------------------+----------------------+----------------+

printer-info text (127)

+----------------------------+----------------------+----------------+

printer-more-info uri

+----------------------------+----------------------+----------------+

printer-driver-installer uri

+----------------------------+----------------------+----------------+

printer-make-and-model text (127)

+----------------------------+----------------------+----------------+

printer-more-info- uri

manufacturer

+----------------------------+----------------------+----------------+

printer-state type1 enum REQUIRED

+----------------------------+----------------------+----------------+

printer-state-reasons 1setOf type2 keyword

+----------------------------+----------------------+----------------+

printer-state-message text (MAX)

+----------------------------+----------------------+----------------+

operations-supported 1setOf type2 enum REQUIRED

+----------------------------+----------------------+----------------+

charset-configured charset REQUIRED

+----------------------------+----------------------+----------------+

charset-supported 1setOf charset REQUIRED

+----------------------------+----------------------+----------------+

natural-language-configured naturalLanguage REQUIRED

+----------------------------+----------------------+----------------+

generated-natural-language- 1setOf REQUIRED

supported naturalLanguage

+----------------------------+----------------------+----------------+

document-format-default mimeMediaType REQUIRED

+----------------------------+----------------------+----------------+

document-format- 1setOf REQUIRED

supported mimeMediaType

+----------------------------+----------------------+----------------+

printer-is-accepting-jobs boolean REQUIRED

+----------------------------+----------------------+----------------+

queued-job-count integer (0:MAX) RECOMMENDED

+----------------------------+----------------------+----------------+

+----------------------------+----------------------+----------------+

Attribute Syntax REQUIRED?

+----------------------------+----------------------+----------------+

printer-message-from- text (127)

operator

+----------------------------+----------------------+----------------+

color-supported boolean

+----------------------------+----------------------+----------------+

reference-uri-schemes- 1setOf uriScheme

supported

+----------------------------+----------------------+----------------+

pdl-override-supported type2 keyword REQUIRED

+----------------------------+----------------------+----------------+

printer-up-time integer (1:MAX) REQUIRED

+----------------------------+----------------------+----------------+

printer-current-time dateTime

+----------------------------+----------------------+----------------+

multiple-operation-time-out integer (1:MAX)

+----------------------------+----------------------+----------------+

compression-supported 1setOf type3 keyword

+----------------------------+----------------------+----------------+

job-k-octets-supported rangeOfInteger

(0:MAX)

+----------------------------+----------------------+----------------+

job-impressions-supported rangeOfInteger

(0:MAX)

+----------------------------+----------------------+----------------+

job-media-sheets-supported rangeOfInteger

(0:MAX)

+----------------------------+----------------------+----------------+

4.4.1 printer-uri-supported (1setOf uri)

This REQUIRED Printer attribute contains at least one URI for the

Printer object. It OPTIONALLY contains more than one URI for the

Printer object. An administrator determines a Printer object's

URI(s) and configures this attribute to contain those URIs by some

means outside the scope of IPP/1.0. The precise format of this URI

is implementation dependent and depends on the protocol. See the

next section for a description "uri-security-supported" which is the

REQUIRED companion attribute to this "printer-uri-supported"

attribute. See section 2.4 on Printer object identity and section

8.2 on security and URIs for more information.

4.4.2 uri-security-supported (1setOf type2 keyword)

This REQUIRED Printer attribute MUST have the same cardinality

(contain the same number of values) as the "printer-uri-supported"

attribute. This attribute identifies the security mechanisms used

for each URI listed in the "printer-uri-supported" attribute. The "i

th" value in "uri-security-supported" corresponds to the "i th" value

in "printer-uri-supported" and it describes the security mechanisms

used for accessing the Printer object via that URI. The following

standard values are defined:

'none': There are no secure communication channel protocols in use

for the given URI.

'ssl3': SSL3 [SSL] is the secure communications channel protocol in

use for the given URI.

Consider the following example. For a single Printer object, an

administrator configures the "printer-uri-supported" and "uri-

security-supported" attributes as follows:

"printer-uri-supported": 'http://acme.com/open-use-printer', '

http://acme.com/restricted-use-printer', '

http://acme.com/private-printer'

"uri-security-supported": 'none', 'none', 'ssl3'

In this case, one Printer object has three URIs.

- For the first URI, 'http://acme.com/open-use-printer', the value

'none' in "uri-security-supported" indicates that there is no

secure channel protocol configured to run under HTTP. The name

implies that there is no Basic or Digest authentication being

used, but it is up to the client to determine that while using

HTTP underneath the IPP application protocol.

- For the second URI, 'http://acme.com/restricted-use-printer', the

value 'none' in "uri-security-supported" indicates that there is

no secure channel protocol configured to run under HTTP. In

this case, although the name does imply that there is some sort

of Basic or Digest authentication being used within HTTP, it is

up to the client to determine that while using HTTP and by

processing any '401 Unauthorized' HTTP error messages.

- For the third URI, 'http://acme.com/private-printer', the value '

ssl3' in "uri-security-supported" indicates that SSL3 is being

used to secure the channel. The client SHOULD be prepared to

use SSL3 framing to negotiate an acceptable ciphersuite to use

while communicating with the Printer object. In this case, the

name implies the use of a secure communications channel, but the

fact is made explicit by the presence of the 'ssl3' value in

"uri-security-supported". The client does not need to resort to

understanding which security it must use by following naming

conventions or by parsing the URI to determine which security

mechanisms are implied.

It is expected that many IPP Printer objects will be configured to

support only one channel (either configured to use SSL3 access or

not), and will therefore only ever have one URI listed in the

"printer-uri-supported" attribute. No matter the configuration of

the Printer object (whether it has only one URI or more than one

URI), a client MUST supply only one URI in the target "printer-uri"

operation attribute.

4.4.3 printer-name (name(127))

This REQUIRED Printer attribute contains the name of the Printer

object. It is a name that is more end-user friendly than a URI. An

administrator determines a printer's name and sets this attribute to

that name. This name may be the last part of the printer's URI or it

may be unrelated. In non-US-English locales, a name may contain

characters that are not allowed in a URI.

4.4.4 printer-location (text(127))

This Printer attribute identifies the location of the device. This

could include things like: "in Room 123A, second floor of building

XYZ".

4.4.5 printer-info (text(127))

This Printer attribute identifies the descriptive information about

this Printer object. This could include things like: "This printer

can be used for printing color transparencies for HR presentations",

or "Out of courtesy for others, please print only small (1-5 page)

jobs at this printer", or even "This printer is going away on July 1,

1997, please find a new printer".

4.4.6 printer-more-info (uri)

This Printer attribute contains a URI used to obtain more information

about this specific Printer object. For example, this could be an

HTTP type URI referencing an HTML page accessible to a Web Browser.

The information obtained from this URI is intended for end user

consumption. Features outside the scope of IPP can be accessed from

this URI. The information is intended to be specific to this printer

instance and site specific services (e.g. job pricing, services

offered, end user assistance). The device manufacturer may initially

populate this attribute.

4.4.7 printer-driver-installer (uri)

This Printer attribute contains a URI to use to locate the driver

installer for this Printer object. This attribute is intended for

consumption by automata. The mechanics of print driver installation

is outside the scope of IPP. The device manufacturer may initially

populate this attribute.

4.4.8 printer-make-and-model (text(127))

This Printer attribute identifies the make and model of the device.

The device manufacturer may initially populate this attribute.

4.4.9 printer-more-info-manufacturer (uri)

This Printer attribute contains a URI used to obtain more information

about this type of device. The information obtained from this URI is

intended for end user consumption. Features outside the scope of IPP

can be accessed from this URI (e.g., latest firmware, upgrades, print

drivers, optional features available, details on color support). The

information is intended to be germane to this printer without regard

to site specific modifications or services. The device manufacturer

may initially populate this attribute.

4.4.10 printer-state (type1 enum)

This REQUIRED Printer attribute identifies the current state of the

device. The "printer-state reasons" attribute augments the

"printer-state" attribute to give more detailed information about the

Printer in the given printer state.

A Printer object need only update this attribute before responding to

an operation which requests the attribute; the Printer object NEED

NOT update this attribute continually, since asynchronous event

notification is not part of IPP/1.0. A Printer NEED NOT implement

all values if they are not applicable to a given implementation.

The following standard enum values are defined:

Value Symbolic Name and Description

'3' 'idle': If a Printer receives a job (whose required

resources are ready) while in this state, such a job

MUST transit into the 'processing' state immediately.

If the "printer-state-reasons" attribute contains any

reasons, they MUST be reasons that would not prevent a

job from transiting into the 'processing' state

immediately, e.g., 'toner-low'. Note: if a Printer

controls more than one output device, the above

definition implies that a Printer is 'idle' if at

least one output device is idle.

'4' 'processing': If a Printer receives a job (whose required

resources are ready) while in this state, such a job

MUST transit into the 'pending' state immediately.

Such a job MUST transit into the 'processing' state

only after jobs ahead of it complete. If the

"printer-state-reasons" attribute contains any

reasons, they MUST be reasons that do not prevent the

current job from printing, e.g. 'toner-low'. Note:

if a Printer controls more than one output device, the

above definition implies that a Printer is '

processing' if at least one output device is

processing, and none is idle.

'5' 'stopped': If a Printer receives a job (whose required

resources are ready) while in this state, such a job

MUST transit into the 'pending' state immediately.

Such a job MUST transit into the 'processing' state

only after some human fixes the problem that stopped

the printer and after jobs ahead of it complete

processing. If supported, the "printer-state-reasons"

attribute MUST contain at least one reason, e.g. '

media-jam', which prevents it from either processing

the current job or transitioning a 'pending' job to

the 'processing' state.

Note: if a Printer controls more than one output

device, the above definition implies that a Printer is

'stopped' only if all output devices are stopped.

Also, it is tempting to define 'stopped' as when a

sufficient number of output devices are stopped and

leave it to an implementation to define the sufficient

number. But such a rule complicates the definition of

'stopped' and 'processing'. For example, with this

alternate definition of 'stopped', a job can move from

'pending' to 'processing' without human intervention,

even though the Printer is stopped.

4.4.11 printer-state-reasons (1setOf type2 keyword)

This Printer attribute supplies additional detail about the device's

state.

Each keyword value MAY have a suffix to indicate its level of

severity. The three levels are: report (least severe), warning, and

error (most severe).

- '-report': This suffix indicates that the reason is a "report".

An implementation may choose to omit some or all reports. Some

reports specify finer granularity about the printer state;

others serve as a precursor to a warning. A report MUST contain

nothing that could affect the printed output.

- '-warning': This suffix indicates that the reason is a "warning".

An implementation may choose to omit some or all warnings.

Warnings serve as a precursor to an error. A warning MUST

contain nothing that prevents a job from completing, though in

some cases the output may be of lower quality.

- '-error': This suffix indicates that the reason is an "error".

An implementation MUST include all errors. If this attribute

contains one or more errors, printer MUST be in the stopped

state.

If the implementation does not add any one of the three suffixes, all

parties MUST assume that the reason is an "error".

If a Printer object controls more than one output device, each value

of this attribute MAY apply to one or more of the output devices. An

error on one output device that does not stop the Printer object as a

whole MAY appear as a warning in the Printer's "printer-state-reasons

attribute". If the "printer-state" for such a Printer has a value of

'stopped', then there MUST be an error reason among the values in the

"printer-state-reasons" attribute.

The following standard keyword values are defined:

'other': The device has detected an error other than one listed in

this document.

'none': There are not reasons. This state reason is semantically

equivalent to "printer-state-reasons" without any value.

'media-needed': A tray has run out of media.

'media-jam': The device has a media jam.

'paused': Someone has paused the Printer object. In this state, a

Printer MUST NOT produce printed output, but it MUST perform

other operations requested by a client. If a Printer had been

printing a job when the Printer was paused, the Printer MUST

resume printing that job when the Printer is no longer paused

and leave no evidence in the printed output of such a pause.

'shutdown': Someone has removed a Printer object from service, and

the device may be powered down or physically removed. In this

state, a Printer object MUST NOT produce printed output, and

unless the Printer object is realized by a print server that is

still active, the Printer object MUST perform no other

operations requested by a client, including returning this

value. If a Printer object had been printing a job when it was

shutdown, the Printer NEED NOT resume printing that job when the

Printer is no longer shutdown. If the Printer resumes printing

such a job, it may leave evidence in the printed output of such

a shutdown, e.g. the part printed before the shutdown may be

printed a second time after the shutdown.

'connecting-to-device': The Printer object has scheduled a job on

the output device and is in the process of connecting to a

shared network output device (and might not be able to actually

start printing the job for an arbitrarily long time depending on

the usage of the output device by other servers on the network).

'timed-out': The server was able to connect to the output device

(or is always connected), but was unable to get a response from

the output device.

'stopping': The Printer object is in the process of stopping the

device and will be stopped in a while. When the device is

stopped, the Printer object will change the Printer object's

state to 'stopped'. The 'stopping-warning' reason is never an

error, even for a Printer with a single output device. When an

output-device ceases accepting jobs, the Printer will have this

reason while the output device completes printing.

'stopped-partly': When a Printer object controls more than one

output device, this reason indicates that one or more output

devices are stopped. If the reason is a report, fewer than half

of the output devices are stopped. If the reason is a warning,

fewer than all of the output devices are stopped.

'toner-low': The device is low on toner.

'toner-empty': The device is out of toner.

'spool-area-full': The limit of persistent storage allocated for

spooling has been reached.

'cover-open': One or more covers on the device are open.

'interlock-open': One or more interlock devices on the printer are

unlocked.

'door-open': One or more doors on the device are open.

'input-tray-missing': One or more input trays are not in the

device.

'media-low': At least one input tray is low on media.

'media-empty': At least one input tray is empty.

'output-tray-missing': One or more output trays are not in the

device

'output-area-almost-full': One or more output area is almost full

(e.g. tray, stacker, collator).

'output-area-full': One or more output area is full. (e.g. tray,

stacker, collator)

'marker-supply-low': The device is low on at least one marker

supply. (e.g. toner, ink, ribbon)

'marker-supply-empty: The device is out of at least one marker

supply. (e.g. toner, ink, ribbon)

'marker-waste-almost-full': The device marker supply waste

receptacle is almost full.

'marker-waste-full': The device marker supply waste receptacle is

full.

'fuser-over-temp': The fuser temperature is above normal.

'fuser-under-temp': The fuser temperature is below normal.

'opc-near-eol': The optical photo conductor is near end of life.

'opc-life-over': The optical photo conductor is no longer

functioning.

'developer-low': The device is low on developer.

'developer-empty: The device is out of developer.

'interpreter-resource-unavailable': An interpreter resource is

unavailable (i.e. font, form)

4.4.12 printer-state-message (text(MAX))

This Printer attribute specifies the additional information about the

printer state and printer state reasons in human readable text. If

the Printer object supports this attribute, the Printer object MUST

be able to generate this message in any of the natural languages

identified by the Printer's "generated-natural-language-supported"

attribute (see the "attributes-natural-language" operation attribute

specified in Section 3.1.4.1).

4.4.13 operations-supported (1setOf type2 enum)

This REQUIRED Printer attribute specifies the set of supported

operations for this Printer object and contained Job objects. All

32-bit enum values for this attribute MUST NOT exceed 0x8FFF, since

these values are passed in two octets in each Protocol request

[RFC2565].

The following standard enum and "operation-id" (see section 3.1.2)

values are defined:

Value Operation Name

----------------- -------------------------------------

0x0000 reserved, not used

0x0001 reserved, not used

0x0002 Print-Job

0x0003 Print-URI

0x0004 Validate-Job

0x0005 Create-Job

0x0006 Send-Document

0x0007 Send-URI

0x0008 Cancel-Job

0x0009 Get-Job-Attributes

0x000A Get-Jobs

0x000B Get-Printer-Attributes

0x000C-0x3FFF reserved for future operations

0x4000-0x8FFF reserved for private extensions

This allows for certain vendors to implement private extensions that

are guaranteed to not conflict with future registered extensions.

However, there is no guarantee that two or more private extensions

will not conflict.

4.4.14 charset-configured (charset)

This REQUIRED Printer attribute identifies the charset that the

Printer object has been configured to represent 'text' and 'name'

Printer attributes that are set by the operator, system

administrator, or manufacturer, i.e., for "printer-name" (name),

"printer-location" (text), "printer-info" (text), and "printer-make-

and-model" (text). Therefore, the value of the Printer object's

"charset-configured" attribute MUST also be among the values of the

Printer object's "charset-supported" attribute.

4.4.15 charset-supported (1setOf charset)

This REQUIRED Printer attribute identifies the set of charsets that

the Printer and contained Job objects support in attributes with

attribute syntax 'text' and 'name'. At least the value 'utf-8' MUST

be present, since IPP objects MUST support the UTF-8 [RFC2279]

charset. If a Printer object supports a charset, it means that for

all attributes of syntax 'text' and 'name' the IPP object MUST (1)

accept the charset in requests and return the charset in responses as

needed.

If more charsets than UTF-8 are supported, the IPP object MUST

perform charset conversion between the charsets as described in

Section 3.2.1.2.

4.4.16 natural-language-configured (naturalLanguage)

This REQUIRED Printer attribute identifies the natural language that

the Printer object has been configured to represent 'text' and 'name'

Printer attributes that are set by the operator, system

administrator, or manufacturer, i.e., for "printer-name" (name),

"printer-location" (text), "printer-info" (text), and "printer-make-

and-model" (text). When returning these Printer attributes, the

Printer object MAY return them in the configured natural language

specified by this attribute, instead of the natural language

requested by the client in the "attributes-natural-language"

operation attribute. See Section 3.1.4.1 for the specification of

the OPTIONAL multiple natural language support. Therefore, the value

of the Printer object's "natural-language-configured" attribute MUST

also be among the values of the Printer object's "generated-natural-

language-supported" attribute.

4.4.17 generated-natural-language-supported (1setOf naturalLanguage)

This REQUIRED Printer attribute identifies the natural language(s)

that the Printer object and contained Job objects support in

attributes with attribute syntax 'text' and 'name'. The natural

language(s) supported depends on implementation and/or configuration.

Unlike charsets, IPP objects MUST accept requests with any natural

language or any Natural Language Override whether the natural

language is supported or not.

If a Printer object supports a natural language, it means that for

any of the attributes for which the Printer or Job object generates

messages, i.e., for the "job-state-message" and "printer-state-

message" attributes and Operation Messages (see Section 3.1.5) in

operation responses, the Printer and Job objects MUST be able to

generate messages in any of the Printer's supported natural

languages. See section 3.1.4 for the specification of 'text' and '

name' attributes in operation requests and responses.

Note: A Printer object that supports multiple natural languages,

often has separate catalogs of messages, one for each natural

language supported.

4.4.18 document-format-default (mimeMediaType)

This REQUIRED Printer attribute identifies the document format that

the Printer object has been configured to assume if the client does

not supply a "document-format" operation attribute in any of the

operation requests that supply document data. The standard values

for this attribute are Internet Media types (sometimes called MIME

types). For further details see the description of the '

mimeMediaType' attribute syntax in Section 4.1.9.

4.4.19 document-format-supported (1setOf mimeMediaType)

This REQUIRED Printer attribute identifies the set of document

formats that the Printer object and contained Job objects can

support. For further details see the description of the '

mimeMediaType' attribute syntax in Section 4.1.9.

4.4.20 printer-is-accepting-jobs (boolean)

This REQUIRED Printer attribute indicates whether the printer is

currently able to accept jobs, i.e., is accepting Print-Job, Print-

URI, and Create-Job requests. If the value is 'true', the printer is

accepting jobs. If the value is 'false', the Printer object is

currently rejecting any jobs submitted to it. In this case, the

Printer object returns the 'server-error-not-accepting-jobs' status

code.

Note: This value is independent of the "printer-state" and "printer-

state-reasons" attributes because its value does not affect the

current job; rather it affects future jobs. This attribute may cause

the Printer to reject jobs when the "printer-state" is 'idle' or it

may cause the Printer object to accepts jobs when the "printer-state"

is 'stopped'.

4.4.21 queued-job-count (integer(0:MAX))

This RECOMMENDED Printer attribute contains a count of the number of

jobs that are either 'pending', 'processing', 'pending-held', or '

processing-stopped' and is set by the Printer object.

4.4.22 printer-message-from-operator (text(127))

This Printer attribute provides a message from an operator, system

administrator or "intelligent" process to indicate to the end user

information or status of the printer, such as why it is unavailable

or when it is expected to be available.

4.4.23 color-supported (boolean)

This Printer attribute identifies whether the device is capable of

any type of color printing at all, including highlight color. All

document instructions having to do with color are embedded within the

document PDL (none are external IPP attributes in IPP/1.0).

Note: end-users are able to determine the nature and details of the

color support by querying the "printer-more-info-manufacturer"

Printer attribute.

4.4.24 reference-uri-schemes-supported (1setOf uriScheme)

This Printer attribute specifies which URI schemes are supported for

use in the "document-uri" operation attribute of the Print-URI or

Send-URI operation. If a Printer object supports these optional

operations, it MUST support the "reference-uri-schemes-supported"

Printer attribute with at least the following schemed URI value:

'ftp': The Printer object will use an FTP 'get' operation as

defined in RFC2228 [RFC2228] using FTP URLs as defined by

[RFC2396] and[RFC2316].

The Printer object MAY OPTIONALLY support other URI schemes (see

section 4.1.6).

4.4.25 pdl-override-supported (type2 keyword)

This REQUIRED Printer attribute expresses the ability for a

particular Printer implementation to either attempt to override

document data instructions with IPP attributes or not.

This attribute takes on the following values:

- 'attempted': This value indicates that the Printer object

attempts to make the IPP attribute values take precedence over

embedded instructions in the document data, however there is no

guarantee.

- 'not-attempted': This value indicates that the Printer object

makes no attempt to make the IPP attribute values take precedence

over embedded instructions in the document data.

Section 15 contains a full description of how this attribute

interacts with and affects other IPP attributes, especially the

"ipp-attribute-fidelity" attribute.

4.4.26 printer-up-time (integer(1:MAX))

This REQUIRED Printer attribute indicates the amount of time (in

seconds) that this instance of this Printer implementation has been

up and running. This value is used to populate the Job attributes

"time-at-creation", "time-at-processing", and "time-at-completed".

These time values are all measured in seconds and all have meaning

only relative to this attribute, "printer-up-time". The value is a

monotonically increasing value starting from 1 when the Printer

object is started-up (initialized, booted, etc.).

If the Printer object goes down at some value 'n', and comes back up,

the implementation MAY:

1. Know how long it has been down, and resume at some value greater

than 'n', or

2. Restart from 1.

In the first case, the Printer SHOULD not tweak any existing related

Job attributes ("time-at-creation", "time-at-processing", and "time-

at-completed"). In the second case, the Printer object SHOULD reset

those attributes to 0. If a client queries a time-related Job

attribute and finds the value to be 0, the client MUST assume that

the Job was submitted in some life other than the Printer's current

life.

4.4.27 printer-current-time (dateTime)

This Printer attribute indicates the current absolute wall-clock

time. If an implementation supports this attribute, then a client

could calculate the absolute wall-clock time each Job's "time-at-

creation", "time-at-processing", and "time-at-completed" attributes

by using both "printer-up-time" and this attribute, "printer-

current-time". If an implementation does not support this attribute,

a client can only calculate the relative time of certain events based

on the REQUIRED "printer-up-time" attribute.

4.4.28 multiple-operation-time-out (integer(1:MAX))

This Printer attributes identifies the minimum time (in seconds) that

the Printer object waits for additional Send-Document or Send-URI

operations to follow a still-open multi-document Job object before

taking any recovery actions, such as the ones indicated in section

3.3.1.

It is RECOMMENDED that vendors supply a value for this attribute that

is between 60 and 240 seconds. An implementation MAY allow a system

administrator to set this attribute. If so, the system administrator

MAY be able to set values outside this range.

4.4.29 compression-supported (1setOf type3 keyword)

This Printer attribute identifies the set of supported compression

algorithms for document data. Compression only applies to the

document data; compression does not apply to the encoding of the IPP

operation itself. The supported values are used to validate the

client supplied "compression" operation attributes in Print-Job,

Send-Document, and Send-URI requests.

Standard values are :

'none': no compression is used.

'deflate': ZIP public domain inflate/deflate) compression

technology

'gzip' GNU zip compression technology described in RFC1952

[RFC1952].

'compress': UNIX compression technology

4.4.30 job-k-octets-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds of total

sizes of jobs in K octets, i.e., in units of 1024 octets. The

supported values are used to validate the client supplied "job-k-

octets" operation attributes in create requests. The corresponding

job description attribute "job-k-octets" is defined in section

4.3.17.

4.4.31 job-impressions-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds for the

number of impressions per job. The supported values are used to

validate the client supplied "job-impressions" operation attributes

in create requests. The corresponding job description attribute

"job-impressions" is defined in section 4.3.18.

4.4.32 job-media-sheets-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds for the

number of media sheets per job. The supported values are used to

validate the client supplied "job-media-sheets" operation attributes

in create requests. The corresponding Job attribute "job-media-

sheets" is defined in section 4.3.19.

5. Conformance

This section describes conformance issues and requirements. This

document introduces model entities such as objects, operations,

attributes, attribute syntaxes, and attribute values. These

conformance sections describe the conformance requirements which

apply to these model entities.

5.1 Client Conformance Requirements

A conforming client MUST support all REQUIRED operations as defined

in this document. For each attribute included in an operation

request, a conforming client MUST supply a value whose type and value

syntax conforms to the requirements of the Model document as

specified in Sections 3 and 4. A conforming client MAY supply any

registered extensions and/or private extensions in an operation

request, as long as they meet the requirements in Section 6.

Otherwise, there are no conformance requirements placed on the user

interfaces provided by IPP clients or their applications. For

example, one application might not allow an end user to submit

multiple documents per job, while another does. One application

might first query a Printer object in order to supply a graphical

user interface (GUI) dialogue box with supported and default values

whereas a different implementation might not.

When sending a request, an IPP client NEED NOT supply any attributes

that are indicated as OPTIONALLY supplied by the client.

A client MUST be able to accept any of the attribute syntaxes defined

in Section 4.1, including their full range, that may be returned to

it in a response from a Printer object. In particular for each

attribute that the client supports whose attribute syntax is 'text',

the client MUST accept and process both the 'textWithoutLanguage' and

'textWithLanguage' forms. Similarly, for each attribute that the

client supports whose attribute syntax is 'name', the client MUST

accept and process both the 'nameWithoutLanguage' and '

nameWithLanguage' forms. For presentation purposes, truncation of

long attribute values is not recommended. A recommended approach

would be for the client implementation to allow the user to scroll

through long attribute values.

A query response may contain attribute groups, attributes, and values

that the client does not expect. Therefore, a client implementation

MUST gracefully handle such responses and not refuse to inter-operate

with a conforming Printer that is returning extended registered or

private attributes and/or attribute values that conform to Section 6.

Clients may choose to ignore any parameters, attributes, or values

that they do not understand.

5.2 IPP Object Conformance Requirements

This section specifies the conformance requirements for conforming

implementations with respect to objects, operations, and attributes.

5.2.1 Objects

Conforming implementations MUST implement all of the model objects as

defined in this specification in the indicated sections:

Section 2.1 - Printer Object

Section 2.2 - Job Object

5.2.2 Operations

Conforming IPP object implementations MUST implement all of the

REQUIRED model operations, including REQUIRED responses, as defined

in this specification in the indicated sections:

For a Printer object:

Print-Job (section 3.2.1) REQUIRED

Print-URI (section 3.2.2) OPTIONAL

Validate-Job (section 3.2.3) REQUIRED

Create-Job (section 3.2.4) OPTIONAL

Get-Printer-Attributes (section 3.2.5) REQUIRED

Get-Jobs (section 3.2.6) REQUIRED

For a Job object:

Send-Document (section 3.3.1) OPTIONAL

Send-URI (section 3.3.2) OPTIONAL

Cancel-Job (section 3.3.3) REQUIRED

Get-Job-Attributes (section 3.3.4) REQUIRED

Conforming IPP objects MUST support all REQUIRED operation attributes

and all values of such attributes if so indicated in the description.

Conforming IPP objects MUST ignore all unsupported or unknown

operation attributes or operation attribute groups received in a

request, but MUST reject a request that contains a supported

operation attribute that contains an unsupported value.

The following section on object attributes specifies the support

required for object attributes.

5.2.3 IPP Object Attributes

Conforming IPP objects MUST support all of the REQUIRED object

attributes, as defined in this specification in the indicated

sections.

If an object supports an attribute, it MUST support only those values

specified in this document or through the extension mechanism

described in section 5.2.4. It MAY support any non-empty subset of

these values. That is, it MUST support at least one of the specified

values and at most all of them.

5.2.4 Extensions

A conforming IPP object MAY support registered extensions and private

extensions, as long as they meet the requirements specified in

Section 6.

For each attribute included in an operation response, a conforming

IPP object MUST return a value whose type and value syntax conforms

to the requirement of the Model document as specified in Sections 3

and 4.

5.2.5 Attribute Syntaxes

An IPP object MUST be able to accept any of the attribute syntaxes

defined in Section 4.1, including their full range, in any operation

in which a client may supply attributes or the system administrator

may configure attributes (by means outside the scope of IPP/1.0). In

particular for each attribute that the IPP object supports whose

attribute syntax is 'text', the IPP object MUST accept and process

both the 'textWithoutLanguage' and 'textWithLanguage' forms.

Similarly, for each attribute that the IPP object supports whose

attribute syntax is 'name', the IPP object MUST accept and process

both the 'nameWithoutLanguage' and 'nameWithLanguage' forms.

Furthermore, an IPP object MUST return attributes to the client in

operation responses that conform to the syntax specified in Section

4.1, including their full range if supplied previously by a client.

5.3 Charset and Natural Language Requirements

All clients and IPP objects MUST support the 'utf-8' charset as

defined in section 4.1.7.

IPP objects MUST be able to accept any client request which correctly

uses the "attributes-natural-language" operation attribute or the

Natural Language Override mechanism on any individual attribute

whether or not the natural language is supported by the IPP object.

If an IPP object supports a natural language, then it MUST be able to

translate (perhaps by table lookup) all generated 'text' or 'name'

attribute values into one of the supported languages (see section

3.1.4). That is, the IPP object that supports a natural language

NEED NOT be a general purpose translator of any arbitrary 'text' or '

name' value supplied by the client into that natural language.

However, the object MUST be able to translate (automatically

generate) any of its own attribute values and messages into that

natural language.

5.4 Security Conformance Requirements

Conforming IPP Printer objects MAY support Secure Socket Layer

Version 3 (SSL3) [SSL] access, support access without SSL3 or support

both means of access.

Conforming IPP clients SHOULD support SSL3 access and non-SSL3

access. Note: This client requirement to support both means that

conforming IPP clients will be able to inter-operate with any IPP

Printer object.

For a detailed discussion of security considerations and the IPP

application security profile required for SSL3 support, see section

8.

6. IANA Considerations (registered and private extensions)

This section describes how IPP can be extended to allow the following

registered and private extensions to IPP:

1. keyword attribute values

2. enum attribute values

3. attributes

4. attribute syntaxes

5. operations

6. attribute groups

7. status codes

Extensions registered for use with IPP/1.0 are OPTIONAL for client

and IPP object conformance to the IPP/1.0 Model specification.

These extension procedures are aligned with the guidelines as set

forth by the IESG [RFC2434]. Section 11 describes how to propose new

registrations for consideration. IANA will reject registration

proposals that leave out required information or do not follow the

appropriate format described in Section 11. IPP/1.0 may also be

extended by an appropriate RFCthat specifies any of the above

extensions.

6.1 Typed 'keyword' and 'enum' Extensions

IPP allows for 'keyword' and 'enum' extensions (see sections 4.1.2.3

and 4.1.4). This document uses prefixes to the 'keyword' and 'enum'

basic attribute syntax type in order to communicate extra information

to the reader through its name. This extra information is not

represented in the protocol because it is unimportant to a client or

Printer object. The list below describes the prefixes and their

meaning.

"type1": The IPP specification must be revised to add a new

keyword or a new enum. No private keywords or enums are

allowed.

"type2": Implementers can, at any time, add new keyword or enum

values by proposing the complete specification to IANA:

iana@iana.org

IANA will forward the registration proposal to the IPP

Designated Expert who will review the proposal with a mailing

list that the Designated Expert keeps for this purpose.

Initially, that list will be the mailing list used by the IPP

WG:

ipp@pwg.org

even after the IPP WG is disbanded as permitted by [RFC2434].

The IPP Designated Expert is appointed by the IESG Area Director

responsible for IPP, according to [RFC2434].

When a type2 keyword or enum is approved, the IPP Designated

Expert becomes the point of contact for any future maintenance

that might be required for that registration.

"type3": Implementers can, at any time, add new keyword and enum

values by submitting the complete specification to IANA as for

type2 who will forward the proposal to the IPP Designated

Expert. While no additional technical review is required, the

IPP Designated Expert may, at his/her discretion, forward the

proposal to the same mailing list as for type2 registrations for

advice and comment.

When a type3 keyword or enum is approved by the IPP Designated

Expert, the original proposer becomes the point of contact for

any future maintenance that might be required for that

registration.

For type2 and type3 keywords, the proposer includes the name of the

keyword in the registration proposal and the name is part of the

technical review.

After type2 and type3 enums specifications are approved, the IPP

Designated Expert in consultation with IANA assigns the next

available enum number for each enum value.

IANA will publish approved type2 and type3 keyword and enum

attributes value registration specifications in:

ftp.isi.edu/iana/assignments/ipp/attribute-values/xxx/yyy.txt

where xxx is the attribute name that specifies the initial values and

yyy.txt is a descriptive file name that contains one or more enums or

keywords approved at the same time. For example, if several

additional enums for stapling are approved for use with the

"finishings" attribute (and "finishings-default" and "finishings-

supported" attributes), IANA will publish the additional values in

the file:

ftp.isi.edu/iana/assignments/ipp/attribute-

values/finishings/stapling.txt

Note: Some attributes are defined to be: 'type3 keywords' 'name'

which allows for attribute values to be extended by a site

administrator with administrator defined names. Such names are not

registered with IANA.

By definition, each of the three types above assert some sort of

registry or review process in order for extensions to be considered

valid. Each higher numbered level (1, 2, 3) tends to be decreasingly

less stringent than the previous level. Therefore, any typeN value

MAY be registered using a process for some typeM where M is less than

N, however such registration is NOT REQUIRED. For example, a type3

value MAY be registered in a type 1 manner (by being included in a

future version of an IPP specification), however, it is NOT REQUIRED.

This specification defines keyword and enum values for all of the

above types, including type3 keywords.

For private (unregistered) keyword extensions, implementers SHOULD

use keywords with a suitable distinguishing prefix, such as "xxx-"

where xxx is the (lowercase) fully qualified company name registered

with IANA for use in domain names [RFC1035]. For example, if the

company XYZ Corp. had obtained the domain name "XYZ.com", then a

private keyword 'abc' would be: 'xyz.com-abc'.

Note: RFC1035 [RFC1035] indicates that while upper and lower case

letters are allowed in domain names, no significance is attached to

the case. That is, two names with the same spelling but different

case are to be treated as if identical. Also, the labels in a domain

name must follow the rules for ARPANET host names: They must start

with a letter, end with a letter or digit, and have as interior

characters only letters, digits, and hyphen. Labels must be 63

characters or less. Labels are separated by the "." character.

For private (unregistered) enum extension, implementers MUST use

values in the reserved integer range which is 2**30 to 2**31-1.

6.2 Attribute Extensibility

Attribute names are type2 keywords. Therefore, new attributes may be

registered and have the same status as attributes in this document by

following the type2 extension rules. For private (unregistered)

attribute extensions, implementers SHOULD use keywords with a

suitable distinguishing prefix as described in Section 6.1.

IANA will publish approved attribute registration specifications as

separate files:

ftp.isi.edu/iana/assignments/ipp/attributes/xxx-yyy.txt

where "xxx-yyy" is the new attribute name.

If a new Printer object attribute is defined and its values can be

affected by a specific document format, its specification needs to

contain the following sentence:

"The value of this attribute returned in a Get-Printer-Attributes

response MAY depend on the "document-format" attribute supplied

(see Section 3.2.5.1)."

If the specification does not, then its value in the Get-Printer-

Attributes response MUST NOT depend on the "document-format" supplied

in the request. When a new Job Template attribute is registered, the

value of the Printer attributes MAY vary with "document-format"

supplied in the request without the specification having to indicate

so.

6.3 Attribute Syntax Extensibility

Attribute syntaxes are like type2 enums. Therefore, new attribute

syntaxes may be registered and have the same status as attribute

syntaxes in this document by following the type2 extension rules

described in Section 6.1. The value codes that identify each of the

attribute syntaxes are assigned in the Encoding and Transport

specification [RFC2565], including a designated range for private,

experimental use.

For attribute syntaxes, the IPP Designated Expert in consultation

with IANA assigns the next attribute syntax code in the appropriate

range as specified in [RFC2565]. IANA will publish approved

attribute syntax registration specifications as separate files:

ftp.isi.edu/iana/assignments/ipp/attribute-syntaxes/xxx-yyy.txt

where 'xxx-yyy' is the new attribute syntax name.

6.4 Operation Extensibility

Operations may also be registered following the type2 procedures

described in Section 6.1, though major new operations will usually be

done by a new standards track RFCthat augments this document. For

private (unregistered) operation extensions, implementers MUST use

the range for the "operation-id" in requests specified in Section

4.4.13 "operations-supported" Printer attribute.

For operations, the IPP Designated Expert in consultation with IANA

assigns the next operation-id code as specified in Section 4.4.13.

IANA will publish approved operation registration specifications as

separate files:

ftp.isi.edu/iana/assignments/ipp/operations/Xxx-Yyy.txt

where "Xxx-Yyy" is the new operation name.

6.5 Attribute Groups

Attribute groups passed in requests and responses may be registered

following the type2 procedures described in Section 6.1. The tags

that identify each of the attribute groups are assigned in [RFC2565].

For attribute groups, the IPP Designated Expert in consultation with

IANA assigns the next attribute group tag code in the appropriate

range as specified in [RFC2565]. IANA will publish approved

attribute group registration specifications as separate files:

ftp.isi.edu/iana/assignments/ipp/attribute-group-tags/xxx-yyy-

tag.txt

where 'xxx-yyy-tag' is the new attribute group tag name.

6.6 Status Code Extensibility

Operation status codes may also be registered following the type2

procedures described in Section 6.1. The values for status codes are

allocated in ranges as specified in Section 13 for each status code

class:

"informational" - Request received, continuing process

"successful" - The action was successfully received, understood,

and accepted

"redirection" - Further action must be taken in order to complete

the request

"client-error" - The request contains bad syntax or cannot be

fulfilled

"server-error" - The IPP object failed to fulfill an apparently

valid request

For private (unregistered) operation status code extensions,

implementers MUST use the top of each range as specified in Section

13.

For operation status codes, the IPP Designated Expert in consultation

with IANA assigns the next status code in the appropriate class range

as specified in Section 13. IANA will publish approved status code

registration specifications as separate files:

ftp.isi.edu/iana/assignments/ipp/status-codes/xxx-yyy.txt

where "xxx-yyy" is the new operation status code keyword.

6.7 Registration of MIME types/sub-types for document-formats

The "document-format" attribute's syntax is 'mimeMediaType'. This

means that valid values are Internet Media Types (see Section 4.1.9).

RFC2045 [RFC2045] defines the syntax for valid Internet media types.

IANA is the registry for all Internet media types.

6.8 Registration of charsets for use in 'charset' attribute values

The "attributes-charset" attribute's syntax is 'charset'. This means

that valid values are charsets names. When a charset in the IANA

registry has more than one name (alias), the name labeled as

"(preferred MIME name)", if present, MUST be used (see Section

4.1.7). IANA is the registry for charsets following the procedures

of [RFC2278].

7. Internationalization Considerations

Some of the attributes have values that are text strings and names

which are intended for human understanding rather than machine

understanding (see the 'text' and 'name' attribute syntaxes in

Sections 4.1.1 and 4.1.2).

In each operation request, the client

- identifies the charset and natural language of the request which

affects each supplied 'text' and 'name' attribute value, and

- requests the charset and natural language for attributes returned

by the IPP object in operation responses (as described in Section

3.1.4.1).

In addition, the client MAY separately and individually identify the

Natural Language Override of a supplied 'text' or 'name' attribute

using the 'textWithLanguage' and 'nameWithLanguage' technique

described section 4.1.1.2 and 4.1.2.2 respectively.

All IPP objects MUST support the UTF-8 [RFC2279] charset in all '

text' and 'name' attributes supported. If an IPP object supports

more than the UTF-8 charset, the object MUST convert between them in

order to return the requested charset to the client according to

Section 3.1.4.2. If an IPP object supports more than one natural

language, the object SHOULD return 'text' and 'name' values in the

natural language requested where those values are generated by the

Printer (see Section 3.1.4.1).

For Printers that support multiple charsets and/or multiple natural

languages in 'text' and 'name' attributes, different jobs may have

been submitted in differing charsets and/or natural languages. All

responses MUST be returned in the charset requested by the client.

However, the Get-Jobs operation uses the 'textWithLanguage' and '

nameWithLanguage' mechanism to identify the differing natural

languages with each job attribute returned.

The Printer object also has configured charset and natural language

attributes. The client can query the Printer object to determine

the list of charsets and natural languages supported by the Printer

object and what the Printer object's configured values are. See the

"charset-configured", "charset-supported", "natural-language-

configured", and "generated-natural-language-supported" Printer

description attributes for more details.

The "charset-supported" attributed identifies the supported charsets.

If a charset is supported, the IPP object MUST be capable of

converting to and from that charset into any other supported charset.

In many cases, an IPP object will support only one charset and it

MUST be the UTF-8 charset.

The "charset-configured" attribute identifies the one supported

charset which is the native charset given the current configuration

of the IPP object (administrator defined).

The "generated-natural-language-supported" attribute identifies the

set of supported natural languages for generated messages; it is not

related to the set of natural languages that must be accepted for

client supplied 'text' and 'name' attributes. For client supplied '

text' and 'name' attributes, an IPP object MUST accept ALL supplied

natural languages. Just because a Printer object is currently

configured to support 'en-us' natural language does not mean that the

Printer object should reject a job if the client supplies a job name

that is in 'fr-ca'.

The "natural-language-configured" attribute identifies the one

supported natural language for generated messages which is the native

natural language given the current configuration of the IPP object

(administrator defined).

Attributes of type 'text' and 'name' are populated from different

sources. These attributes can be categorized into following groups

(depending on the source of the attribute):

1. Some attributes are supplied by the client (e.g., the client

supplied "job-name", "document-name", and "requesting-user-name"

operation attributes along with the corresponding Job object's

"job-name" and "job-originating-user-name" attributes). The IPP

object MUST accept these attributes in any natural language no

matter what the set of supported languages for generated

messages

2. Some attributes are supplied by the system administrator (e.g.,

the Printer object's "printer-name" and "printer-location"

attributes). These too can be in any natural language. If the

natural language for these attributes is different than what a

client requests, then they must be reported using the Natural

Language Override mechanism.

3. Some attributes are supplied by the device manufacturer (e.g.,

the Printer object's "printer-make-and-model" attribute). These

too can be in any natural language. If the natural language for

these attributes is different than what a client requests, then

they must be reported using the Natural Language Override

mechanism.

4. Some attributes are supplied by the operator (e.g., the Job

object's "job-message-from-operator" attribute). These too can

be in any natural language. If the natural language for these

attributes is different than what a client requests, then they

must be reported using the Natural Language Override mechanism.

5. Some attributes are generated by the IPP object (e.g., the Job

object's "job-state-message" attribute, the Printer object's

"printer-state-message" attribute, and the "status-message"

operation attribute). These attributes can only be in one of

the "generated-natural-language-supported" natural languages.

If a client requests some natural language for these attributes

other than one of the supported values, the IPP object SHOULD

respond using the value of the "natural-language-configured"

attribute (using the Natural Language Override mechanism if

needed).

The 'text' and 'name' attributes specified in this version of this

document (additional ones will be registered according to the

procedures in Section 6) are:

Attributes Source

-------------------------- ----------

Operation Attributes

job-name (name) client

document-name (name) client

requesting-user-name (name) client

status-message Job or Printer object

Job Template Attributes:

job-hold-until) client matches administrator-configured

(keyword name

job-hold-until-default client matches administrator-configured

(keyword name)

job-hold-until-supported client matches administrator-configured

(keyword name)

job-sheets client matches administrator-configured

(keyword name)

job-sheets-default client matches administrator-configured

(keyword name)

job-sheets-supported client matches administrator-configured

(keyword name)

media client matches administrator-configured

(keyword name)

media-default client matches administrator-configured

(keyword name)

media-supported client matches administrator-configured

(keyword name)

media-ready client matches administrator-configured

(keyword name)

Job Description Attributes:

job-name (name) client or Printer object

job-originating-user-name (name) Printer object

job-state-message (text) Job or Printer object

output-device-assigned (name(127)) administrator

job-message-from-operator (text(127)) operator

Printer Description Attributes:

printer-name (name(127)) administrator

printer-location (text(127)) administrator

printer-info (text(127)) administrator

printer-make-and-model (text(127)) administrator or manufacturer

printer-state-message (text) Printer object

printer-message-from-operator (text(127)) operator

8. Security Considerations

Some IPP objects MAY be deployed over protocol stacks that support

Secure Socket Layer Version 3 (SSL3) [SSL]. Note: SSL3 is not an

IETF standards track specification. Other IPP objects MAY be

deployed over protocol stacks that do not support SSL3. Some IPP

objects MAY be deployed over both types of protocol stacks. Those

IPP objects that support SSL3, are capable of supporting mutual

authentication as well as privacy of messages via multiple encryption

schemes. An important point about security related information for

SSL3 access to an IPP object, is that the security-related parameters

(authentication, encryption keys, etc.) are "out-of-band" to the

actual IPP protocol.

An IPP object that does not support SSL3 MAY elect to support a

transport layer that provides other security mechanisms. For

example, in a mapping of IPP over HTTP/1.1 [RFC2565], if the IPP

object does not support SSL3, HTTP still allows for client

authentication using Digest Access Authentication (DAA) [RFC2069].

It is difficult to anticipate the security risks that might exist in

any given IPP environment. For example, if IPP is used within a given

corporation over a private network, the risks of exposing document

data may be low enough that the corporation will choose not to use

encryption on that data. However, if the connection between the

client and the IPP object is over a public network, the client may

wish to protect the content of the information during transmission

through the network with encryption.

Furthermore, the value of the information being printed may vary from

one IPP environment to the next. Printing payroll checks, for

example, would have a different value than printing public

information from a file. There is also the possibly of denial-of-

service attacks, but denial-of-service attacks against printing

resources are not well understood and there is no published

precedents regarding this scenario.

Once the authenticated identity of the requester has been supplied to

the IPP object, the object uses that identity to enforce any

authorization policy that might be in place. For example, one site's

policy might be that only the job owner is allowed to cancel a job.

The details and mechanisms to set up a particular access control

policy are not part of IPP/1.0, and must be established via some

other type of administrative or access control framework. However,

there are operation status codes that allow an IPP server to return

information back to a client about any potential access control

violations for an IPP object.

During a create operation, the client's identity is recorded in the

Job object in an implementation-defined attribute. This information

can be used to verify a client's identity for subsequent operations

on that Job object in order to enforce any access control policy that

might be in effect. See section 8.3 below for more details.

Since the security levels or the specific threats that any given IPP

system administrator may be concerned with cannot be anticipated, IPP

MUST be capable of operating with different security mechanisms and

security policies as required by the individual installation.

Security policies might vary from very strong, to very weak, to none

at all, and corresponding security mechanisms will be required. SSL3

supports the type of negotiated levels of security required by most,

if not all, potential IPP environments. IPP environments that require

no security can elect to deploy IPP objects that do not utilize the

optional SSL3 security mechanisms.

8.1 Security Scenarios

The following sections describe specific security attacks for IPP

environments. Where examples are provided they should be considered

illustrative of the environment and not an exhaustive set. Not all of

these environments will necessarily be addressed in initial

implementations of IPP.

8.1.1 Client and Server in the Same Security Domain

This environment is typical of internal networks where traditional

Office workers print the output of personal productivity applications

on shared work-group printers, or where batch applications print

their output on large production printers. Although the identity of

the user may be trusted in this environment, a user might want to

protect the content of a document against such attacks as

eavesdropping, replaying or tampering.

8.1.2 Client and Server in Different Security Domains

Examples of this environment include printing a document created by

the client on a publicly available printer, such as at a commercial

print shop; or printing a document remotely on a business associate's

printer. This latter operation is functionally equivalent to sending

the document to the business associate as a facsimile. Printing

sensitive information on a Printer in a different security domain

requires strong security measures. In this environment authentication

of the printer is required as well as protection against unauthorized

use of print resources. Since the document crosses security domains,

protection against eavesdropping and document tampering are also

required. It will also be important in this environment to protect

Printers against "spamming" and malicious document content.

8.1.3 Print by Reference

When the document is not stored on the client, printing can be done

by reference. That is, the print request can contain a reference, or

pointer, to the document instead of the actual document itself.

Standard methods currently do not exist for remote entities to

"assume" the credentials of a client for forwarding requests to a 3rd

party. It is anticipated that Print-By-Reference will be used to

access "public" documents and that sophisticated methods for

authenticating "proxies" will not be specified for version 1 of IPP.

8.2 URIs for SSL3 and non-SSL3 Access

As described earlier, an IPP object can support SSL3 access, non-SSL3

access, or both. The "printer-uri-supported" attribute contains the

Printer object's URI(s). Its companion attribute, "uri-security-

supported", identifies the security mechanism used for each URI

listed in the "printer-uri-supported" attribute. For each Printer

operation request, a client MUST supply only one URI in the

"printer-uri" operation attribute. In other words, even though the

Printer supports more than one URI, the client only interacts with

the Printer object using one if its URIs. This duality is not needed

for Job objects, since the Printer objects is the factory for Job

objects, and the Printer object will generate the correct URI for new

Job objects depending on the Printer object's security configuration.

8.3 The "requesting-user-name" (name(MAX)) Operation Attribute

Each operation MUST specify the user who is performing the operation

in both of the following two ways:

1) via the REQUIRED "requesting-user-name" operation attribute that

a client SHOULD supply in all operations. The client MUST obtain

the value for this attribute from an environmental or network

login name for the user, rather than allowing the user to supply

any value. If the client does not supply a value for

"requesting-user-name", the printer MUST assume that the client

is supplying some anonymous name, such as "anonymous".

2) via an authentication mechanism of the underlying transport

which may be configured to give no authentication information.

There are six cases to consider:

a) the authentication mechanism gives no information, and the

client doesn't specify "requesting-user-name".

b) the authentication mechanism gives no information, but the

client specifies "requesting-user-name".

c) the authentication mechanism specifies a user which has no human

readable representation, and the client doesn't specify

"requesting-user-name".

d) the authentication mechanism specifies a user which has no human

readable representation, but the client specifies "requesting-

user-name".

e) the authentication mechanism specifies a user which has a human

readable representation. The Printer object ignores the

"requesting-user-name".

f) the authentication mechanism specifies a user who is trusted and

whose name means that the value of the "requesting-user-name",

which MUST be present, is treated as the authenticated name.

Note: Case "f" is intended for a tightly coupled gateway and server

to work together so that the "user" name is able to be that of the

gateway client and not that of the gateway. Because most, if not

all, system vendors will initially implement IPP via a gateway into

their existing print system, this mechanism is necessary unless the

authentication mechanism allows a gateway (client) to act on behalf

of some other client.

The user-name has two forms:

- one that is human readable: it is held in the REQUIRED "job-

originating-user-name" Job Description attribute which is set

during the job creation operations. It is used for presentation

only, such as returning in queries or printing on start sheets

- one for authorization: it is held in an undefined (by IPP) Job

object attribute which is set by the job creation operation. It

is used to authorize other operations, such as Send-Document,

Send-URI, Cancel-Job, to determine the user when the "my-jobs"

attribute is specified with Get-Jobs, and to limit what

attributes and values to return with Get-Job-Attributes and Get-

Jobs.

The human readable user name:

- is the value of the "requesting-user-name" for cases b, d and f.

- comes from the authentication mechanism for case e

- is some anonymous name, such as "anonymous" for cases a and c.

The user name used for authorization:

- is the value of the "requesting-user-name" for cases b and f.

- comes from the authentication mechanism for cases c, d and e

- is some anonymous name, such as "anonymous" for case a.

The essence of these rules for resolving conflicting sources of

user-names is that a printer implementation is free to pick either

source as long as it achieves consistent results. That is, if a user

uses the same path for a series of requests, the requests MUST appear

to come from the same user from the standpoint of both the human-

readable user name and the user name for authorization. This rule

MUST continue to apply even if a request could be authenticated by

two or more mechanisms. It doesn't matter which of several

authentication mechanisms a Printer uses as long as it achieves

consistent results. If a client uses more than one authentication

mechanism, it is recommended that an administrator make all

credentials resolve to the same user and user-name as much as

possible.

8.4 Restricted Queries

In many IPP operations, a client supplies a list of attributes to be

returned in the response. For security reasons, an IPP object may be

configured not to return all attributes (or all values) that a client

requests. The job attributes returned MAY depend on whether the

requesting user is the same as the user that submitted the job. The

IPP object MAY even return none of the requested attributes. In such

cases, the status returned is the same as if the object had returned

all requested attributes. The client cannot tell by such a response

whether the requested attribute was present or absent on the object.

8.5 Queries on jobs submitted using non-IPP protocols

If the device that an IPP Printer is representing is able to accept

jobs using other job submission protocols in addition to IPP, it is

RECOMMENDED that such an implementation at least allow such "foreign"

jobs to be queried using Get-Jobs returning "job-id" and "job-uri" as

'unknown'. Such an implementation NEED NOT support all of the same

IPP job attributes as for IPP jobs. The IPP object returns the '

unknown' out-of-band value for any requested attribute of a foreign

job that is supported for IPP jobs, but not for foreign jobs.

It is further RECOMMENDED, that the IPP Printer generate "job-id" and

"job-uri" values for such "foreign jobs", if possible, so that they

may be targets of other IPP operations, such as Get-Job-Attributes

and Cancel-Job. Such an implementation also needs to deal with the

problem of authentication of such foreign jobs. One approach would

be to treat all such foreign jobs as belonging to users other than

the user of the IPP client. Another approach would be for the

foreign job to belong to 'anonymous'. Only if the IPP client has

been authenticated as an operator or administrator of the IPP Printer

object, could the foreign jobs be queried by an IPP request.

Alternatively, if the security policy is to allow users to query

other users' jobs, then the foreign jobs would also be visible to an

end-user IPP client using Get-Jobs and Get-Job-Attributes.

8.6 IPP Security Application Profile for SSL3

The IPP application profile for SSL3 follows the "Secure Socket

Layer" requirement as documented in the SSL3 specification [SSL].

For interoperability, the SSL3 cipher suites are:

SSL_RSA_WITH_RC4_128_MD5

SSL_RSA_WITH_3DES_EDE_CBC_SHA

SSL_RSA_WITH_DES_CBC_SHA

SSL_RSA_EXPORT_WITH_RC4_40_MD5

SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5

SSL_RSA_WITH_NULL_MD5

Client implementations MUST NOT assume any other cipher suites are

supported by an IPP Printer object.

If a conforming IPP object supports SSL3, it MUST implement and

support the cipher suites listed above and MAY support additional

cipher suites.

A conforming IPP client SHOULD support SSL3 including the cipher

suites listed above. A conforming IPP client MAY support additional

cipher suites.

It is possible that due to certain government export restrictions

some non-compliant versions of this extension could be deployed.

Implementations wishing to inter-operate with such non-compliant

versions MAY offer the SSL_RSA_EXPORT_WITH_RC4_40_MD5 and

SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5 mechanisms. However, since 40 bit

ciphers are known to be vulnerable to attack by current technology,

any client which actives a 40 bit cipher MUST NOT indicate to the

user that the connection is completely secure from eavesdropping.

9. References

[ASCII] Coded Character Set - 7-bit American Standard Code for

Information Interchange (ASCII), ANSI X3.4-1986. This

standard is the specification of the US-ASCII charset.

[HTPP] J. Barnett, K. Carter, R. DeBry, "Initial Draft -

Hypertext Printing Protocol - HTPP/1.0", October 1996.

ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/

overview.ps.gz

[IANA-CS] IANA Registry of Coded Character Sets:

ftp://ftp.isi.edu/in-notes/iana/assignments/character-

sets

[IANA-MT] IANA Registry of Media Types: ftp://ftp.isi.edu/in-

notes/iana/assignments/media-types/

[ipp-iig] Hastings, T. and C. Manros, "Internet Printing

Protocol/1.0: Implementer's Guide", Work in Progress.

[ISO10646-1] ISO/IEC 10646-1:1993, "Information technology --

Universal Multiple-Octet Coded Character Set (UCS) -

Part 1: Architecture and Basic Multilingual Plane,

JTC1/SC2."

[ISO8859-1] ISO/IEC 8859-1:1987, "Information technology -- 8-bit

One-Byte Coded Character Set - Part 1: Latin Alphabet Nr

1", 1987, JTC1/SC2.

[ISO10175] ISO/IEC 10175 Document Printing Application (DPA), June

1996.

[LDPA] T. Hastings, S. Isaacson, M. MacKay, C. Manros, D. Taylor, P.

Zehler, "LDPA - Lightweight Document Printing

Application", October 1996,

ftp://ftp.pwg.org/pub/pwg/ipp/historic/ldpa/ldpa8.pdf.gz

[P1387.4] Kirk, M. (Editor), POSIX System Administration - Part 4:

Printing Interfaces, POSIX 1387.4 D8, 1994.

[PSIS] Herriot, R. (editor), X/Open A Printing System

Interoperability Specification (PSIS), August 1995.

[PWG] Printer Working Group, http://www.pwg.org.

[RFC1035] Mockapetris, P., "DOMAIN NAMES - IMPLEMENTATION AND

SPECIFICATION", STD 13, RFC1035, November 1987.

[RFC1759] Smith, R., Wright, F., Hastings, T., Zilles, S. and J.

Gyllenskog, "Printer MIB", RFC1759, March 1995.

[RFC1766] Alvestrand, H., "Tags for the Identification of

Languages", RFC1766, March 1995.

[RFC1179] McLaughlin, L. (Editor), "Line Printer Daemon Protocol",

RFC1179, August 1990.

[RFC1952] Deutsch, P., "GZIP file format specification version

4.3", RFC1952, May 1996.

[RFC2045] Freed, N. and N. Borenstein, " Multipurpose Internet

Mail Extensions (MIME) Part One: Format of Internet

Message Bodies", RFC2045, November 1996.

[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail

Extensions (MIME) Part Two: Media Types", RFC2046,

November 1996.

[RFC2048] Freed, N., Klensin, J. and J. Postel, "Multipurpose

Internet Mail Extension (MIME) Part Four: Registration

Procedures", RFC2048, November 1996.

[RFC2068] Fielding, R., Gettys, J., Mogul, J., Frystyk, H. AND T.

Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1",

RFC2068, January 1997.

[RFC2069] Franks, J., Hallam-Baker, P., Hostetler, J., Leach, P.,

Luotonen, A., Sink, E. and L. Stewart, "An Extension to

HTTP: Digest Access Authentication", RFC2069, January

1997.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate

Requirement Levels", BCP 14, RFC2119, March 1997.

[RFC2228] Horowitz, M. and S. Lunt, "FTP Security Extensions", RFC

2228, October 1997.

[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and

Languages" RFC2277, January 1998.

[RFC2278] Freed, N. and J. Postel: "IANA Charset Registration

Procedures", BCP 19, RFC2278, January 1998.

[RFC2279] Yergeau, F., "UTF-8, a transformation format of ISO

10646", RFC2279, January 1998.

[RFC2316] Bellovin, S., "Report of the IAB Security Architecture

Workshop", RFC2316, April 1998.

[RFC2396] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform

Resource Identifiers (URI): Generic Syntax", RFC2396,

August 1998.

[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an

IANA Considerations Section in RFCs", BCP 26, RFC2434,

October 1998.

[RFC2565] Herriot, R., Butler, S., Moore, P. and R. Tuner

"Internet Printing Protocol/1.0: Encoding and

Transport", RFC2565, April 1999.

[RFC2567] Wright, D., "Design Goals for an Internet Printing

Protocol", RFC2567, April 1999.

[RFC2568] Zilles, S., "Rationale for the Structure and Model and

Protocol for the Internet Printing Protocol", RFC2568,

April 1999.

[RFC2569] Herriot, R., Hastings, T., Jacobs, N. and J. Martin,

"Mapping between LPD and IPP Protocols", RFC2569, April

1999.

[RFC2579] McCloghrie, K., Perkins, D. and J. Schoenwaelder,

"Textual Conventions for SMIv2", STD 58, RFC2579, April

1999.

[SSL] Netscape, The SSL Protocol, Version 3, (Text version

3.02), November 1996.

[SWP] P. Moore, B. Jahromi, S. Butler, "Simple Web Printing

SWP/1.0", May 7, 1997,

ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/swp9705.pdf

10. Authors' Addresses

Scott A. Isaacson (Editor)

Novell, Inc.

122 E 1700 S

Provo, UT 84606

Phone: 801-861-7366

Fax: 801-861-2517

EMail: sisaacson@novell.com

Tom Hastings

Xerox Corporation

737 Hawaii St.

El Segundo, CA 90245

Phone: 310-333-6413

Fax: 310-333-5514

EMail: hastings@cp10.es.xerox.com

Robert Herriot

Xerox Corporation

3400 Hillview Ave., Bldg #1

Palo Alto, CA 94304

Phone: 650-813-7696

Fax: 650-813-6860

EMail: robert.herriot@pahv.xerox.com

Roger deBry

Utah Valley State College

Orem, UT 84058

Phone: (801) 222-8000

EMail: debryro@uvsc.edu

Patrick Powell

Astart Technologies

9475 Chesapeake Dr., Suite D

San Diego, CA 95123

Phone: (619) 874-6543

Fax: (619) 279-8424

EMail: papowell@astart.com

IPP Mailing List: ipp@pwg.org

IPP Mailing List Subscription: ipp-request@pwg.org

IPP Web Page: http://www.pwg.org/ipp/

Implementers of this specification are encouraged to join IPP Mailing

List in order to participate in any discussions of clarification

issues and review of registration proposals for additional attributes

and values.

Other Participants:

Chuck Adams - Tektronix

Jeff Barnett - IBM

Ron Bergman - Dataproducts Corp.

Sylvan Butler - HP

Keith Carter - IBM Corporation

Jeff Copeland - QMS

Andy Davidson - Tektronix

Mabry Dozier - QMS

Lee Farrell - Canon Information Systems

Steve Gebert - IBM

Babek Jahromi - Microsoft

David Kellerman - Northlake Software

Rick Landau - Digital

Greg LeClair - Epson

Harry Lewis - IBM

Pete Loya - HP

Ray Lutz - Cognisys

Mike MacKay - Novell, Inc.

Daniel Manchala - Xerox

Carl-Uno Manros - Xerox

Jay Martin - Underscore

Larry Masinter - Xerox

Stan McConnell - Xerox

Ira McDonald - High North Inc.

Paul Moore - Microsoft

Tetsuya Morita - Ricoh

Yuichi Niwa - Ricoh

Pat Nogay - IBM

Ron Norton - Printronics

Bob Pentecost - HP

Rob Rhoads - Intel

Xavier Riley - Xerox

David Roach - Unisys

Stuart Rowley - Kyocera

Hiroyuki Sato - Canon

Bob Setterbo - Adobe

Devon Taylor - Novell, Inc.

Mike Timperman - Lexmark

Randy Turner - Sharp

Atsushi Yuki - Kyocera

Rick Yardumian - Xerox

Lloyd Young - Lexmark

Bill Wagner - DPI

Jim Walker - DAZEL

Chris Wellens - Interworking Labs

Rob Whittle - Novell, Inc.

Don Wright - Lexmark

Peter Zehler - Xerox

Steve Zilles - Adobe

11. Formats for IPP Registration Proposals

In order to propose an IPP extension for registration, the proposer

must submit an application to IANA by email to "iana@iana.org" or by

filling out the appropriate form on the IANA web pages

(http://www.iana.org). This section specifies the required

information and the formats for proposing registrations of extensions

to IPP as provided in Section 6 for:

1. type2 'keyword' attribute values

2. type3 'keyword' attribute values

3. type2 'enum' attribute values

4. type3 'enum' attribute values

5. attributes

6. attribute syntaxes

7. operations

8. status codes

11.1 Type2 keyword attribute values registration

Type of registration: type2 keyword attribute value

Name of attribute to which this keyword specification is to be added:

Proposed keyword name of this keyword value:

Specification of this keyword value (follow the style of IPP Model

Section 4.1.2.3):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For type2 keywords, the Designated Expert will be the point of

contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.2 Type3 keyword attribute values registration

Type of registration: type3 keyword attribute value

Name of attribute to which this keyword specification is to be added:

Proposed keyword name of this keyword value:

Specification of this keyword value (follow the style of IPP Model

Section 4.1.2.3):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For type3 keywords, the proposer will be the point of contact

for the approved registration specification, if any maintenance of

the registration specification is needed.

11.3 Type2 enum attribute values registration

Type of registration: type2 enum attribute value

Name of attribute to which this enum specification is to be added:

Keyword symbolic name of this enum value:

Numeric value (to be assigned by the IPP Designated Expert in

consultation with IANA):

Specification of this enum value (follow the style of IPP Model

Section 4.1.4):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For type2 enums, the Designated Expert will be the point of

contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.4 Type3 enum attribute values registration

Type of registration: type3 enum attribute value

Name of attribute to which this enum specification is to be added:

Keyword symbolic name of this enum value:

Numeric value (to be assigned by the IPP Designated Expert in

consultation with IANA):

Specification of this enum value (follow the style of IPP Model

Section 4.1.4):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For type3 enums, the proposer will be the point of contact for

the approved registration specification, if any maintenance of the

registration specification is needed.

11.5 Attribute registration

Type of registration: attribute

Proposed keyword name of this attribute:

Types of attribute (Operation, Job Template, Job Description,

Printer Description):

Operations to be used with if the attribute is an operation

attribute:

Object (Job, Printer, etc. if bound to an object):

Attribute syntax(es) (include 1setOf and range as in Section 4.2):

If attribute syntax is 'keyword' or 'enum', is it type2 or type3:

If this is a Printer attribute, MAY the value returned depend on

"document-format" (See Section 6.2):

If this is a Job Template attribute, how does its specification

depend on the value of the "multiple-document-handling" attribute:

Specification of this attribute (follow the style of IPP Model

Section 4.2):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For attributes, the IPP Designated Expert will be the point of

contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.6 Attribute Syntax registration

Type of registration: attribute syntax

Proposed name of this attribute syntax:

Type of attribute syntax (integer, octetString, character-string,

see [RFC2565]):

Numeric value (to be assigned by the IPP Designated Expert in

consultation with IANA):

Specification of this attribute (follow the style of IPP Model

Section 4.1):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For attribute syntaxes, the IPP Designated Expert will be the

point of contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.7 Operation registration

Type of registration: operation

Proposed name of this operation:

Numeric operation-id value (to be assigned by the IPP Designated

Expert in consultation with IANA):

Object Target (Job, Printer, etc. that operation is upon):

Specification of this attribute (follow the style of IPP Model

Section 3):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For operations, the IPP Designated Expert will be the point of

contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.8 Attribute Group registration

Type of registration: attribute group

Proposed name of this attribute group:

Numeric tag according to [RFC2565] (to be assigned by the IPP

Designated Expert in consultation with IANA):

Operation requests and group number for each operation in which the

attribute group occurs:

Operation responses and group number for each operation in which the

attribute group occurs:

Specification of this attribute group (follow the style of IPP Model

Section 3):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For attribute groups, the IPP Designated Expert will be the

point of contact for the approved registration specification, if any

maintenance of the registration specification is needed.

11.9 Status code registration

Type of registration: status code

Keyword symbolic name of this status code value:

Numeric value (to be assigned by the IPP Designated Expert in

consultation with IANA):

Operations that this status code may be used with:

Specification of this status code (follow the style of IPP Model

Section 14 APPENDIX B: Status Codes and Suggested Status Code

Messages):

Name of proposer:

Address of proposer:

Email address of proposer:

Note: For status codes, the Designated Expert will be the point of

contact for the approved registration specification, if any

maintenance of the registration specification is needed.

12. APPENDIX A: Terminology

This specification uses the terminology defined in this section.

12.1 Conformance Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",

"RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be

interpreted as described in RFC2119 [RFC2119].

12.1.1 NEED NOT

This term is not included in RFC2119. The verb "NEED NOT" indicates

an action that the subject of the sentence does not have to implement

in order to claim conformance to the standard. The verb "NEED NOT"

is used instead of "MAY NOT" since "MAY NOT" sounds like a

prohibition.

12.2 Model Terminology

12.2.1 Keyword

Keywords are used within this document as identifiers of semantic

entities within the abstract model (see section 4.1.2.3). Attribute

names, some attribute values, attribute syntaxes, and attribute group

names are represented as keywords.

12.2.2 Attributes

An attribute is an item of information that is associated with an

instance of an IPP object. An attribute consists of an attribute

name and one or more attribute values. Each attribute has a specific

attribute syntax. All object attributes are defined in section 4 and

all operation attributes are defined in section 3.

Job Template Attributes are described in section 4.2. The client

optionally supplies Job Template attributes in a create request

(operation requests that create Job objects). The Printer object has

associated attributes which define supported and default values for

the Printer.

12.2.2.1 Attribute Name

Each attribute is uniquely identified in this document by its

attribute name. An attribute name is a keyword. The keyword

attribute name is given in the section header describing that

attribute. In running text in this document, attribute names are

indicated inside double quotation marks (") where the quotation marks

are not part of the keyword itself.

12.2.2.2 Attribute Group Name

Related attributes are grouped into named groups. The name of the

group is a keyword. The group name may be used in place of naming

all the attributes in the group explicitly. Attribute groups are

defined in section 3.

12.2.2.3 Attribute Value

Each attribute has one or more values. Attribute values are

represented in the syntax type specified for that attribute. In

running text in this document, attribute values are indicated inside

single quotation marks ('), whether their attribute syntax is

keyword, integer, text, etc. where the quotation marks are not part

of the value itself.

12.2.2.4 Attribute Syntax

Each attribute is defined using an explicit syntax type. In this

document, each syntax type is defined as a keyword with specific

meaning. The Encoding and Transport document [RFC2565] indicates the

actual "on-the-wire" encoding rules for each syntax type. Attribute

syntax types are defined in section 4.1.

12.2.3 Supports

By definition, a Printer object supports an attribute only if that

Printer object responds with the corresponding attribute populated

with some value(s) in a response to a query for that attribute. A

Printer object supports an attribute value if the value is one of the

Printer object's "supported values" attributes. The device behind a

Printer object may exhibit a behavior that corresponds to some IPP

attribute, but if the Printer object, when queried for that

attribute, doesn't respond with the attribute, then as far as IPP is

concerned, that implementation does not support that feature. If the

Printer object's "xxx-supported" attribute is not populated with a

particular value (even if that value is a legal value for that

attribute), then that Printer object does not support that particular

value.

A conforming implementation MUST support all REQUIRED attributes.

However, even for REQUIRED attributes, conformance to IPP does not

mandate that all implementations support all possible values

representing all possible job processing behaviors and features. For

example, if a given instance of a Printer supports only certain

document formats, then that Printer responds with the "document-

format-supported" attribute populated with a set of values, possibly

only one, taken from the entire set of possible values defined for

that attribute. This limited set of values represents the Printer's

set of supported document formats. Supporting an attribute and some

set of values for that attribute enables IPP end users to be aware of

and make use of those features associated with that attribute and

those values. If an implementation chooses to not support an

attribute or some specific value, then IPP end users would have no

ability to make use of that feature within the context of IPP itself.

However, due to existing practice and legacy systems which are not

IPP aware, there might be some other mechanism outside the scope of

IPP to control or request the "unsupported" feature (such as embedded

instructions within the document data itself).

For example, consider the "finishings-supported" attribute.

1) If a Printer object is not physically capable of stapling, the

"finishings-supported" attribute MUST NOT be populated with the

value of 'staple'.

2) A Printer object is physically capable of stapling, however an

implementation chooses not to support stapling in the IPP

"finishings" attribute. In this case, 'staple' MUST NOT be a

value in the "finishings-supported" Printer object attribute.

Without support for the value 'staple', an IPP end user would

have no means within the protocol itself to request that a Job

be stapled. However, an existing document data formatter might

be able to request that the document be stapled directly with an

embedded instruction within the document data. In this case,

the IPP implementation does not "support" stapling, however the

end user is still able to have some control over the stapling of

the completed job.

3) A Printer object is physically capable of stapling, and an

implementation chooses to support stapling in the IPP

"finishings" attribute. In this case, 'staple' MUST be a value

in the "finishings-supported" Printer object attribute. Doing

so, would enable end users to be aware of and make use of the

stapling feature using IPP attributes.

Even though support for Job Template attributes by a Printer object

is OPTIONAL, it is RECOMMENDED that if the device behind a Printer

object is capable of realizing any feature or function that

corresponds to an IPP attribute and some associated value, then that

implementation SHOULD support that IPP attribute and value.

The set of values in any of the supported value attributes is set

(populated) by some administrative process or automatic sensing

mechanism that is outside the scope of IPP. For administrative

policy and control reasons, an administrator may choose to make only

a subset of possible values visible to the end user. In this case,

the real output device behind the IPP Printer abstraction may be

capable of a certain feature, however an administrator is specifying

that access to that feature not be exposed to the end user through

the IPP protocol. Also, since a Printer object may represent a

logical print device (not just a physical device) the actual process

for supporting a value is undefined and left up to the

implementation. However, if a Printer object supports a value, some

manual human action may be needed to realize the semantic action

associated with the value, but no end user action is required.

For example, if one of the values in the "finishings-supported"

attribute is 'staple', the actual process might be an automatic

staple action by a physical device controlled by some command sent to

the device. Or, the actual process of stapling might be a manual

action by an operator at an operator attended Printer object.

For another example of how supported attributes function, consider a

system administrator who desires to control all print jobs so that no

job sheets are printed in order to conserve paper. To force no job

sheets, the system administrator sets the only supported value for

the "job-sheets-supported" attribute to 'none'. In this case, if a

client requests anything except 'none', the create request is

rejected or the "job-sheets" value is ignored (depending on the value

of "ipp-attribute-fidelity"). To force the use of job start/end

sheets on all jobs, the administrator does not include the value '

none' in the "job-sheets-supported" attribute. In this case, if a

client requests 'none', the create request is rejected or the "job-

sheets" value is ignored (again depending on the value of "ipp-

attribute-fidelity").

12.2.4 print-stream page

A "print-stream page" is a page according to the definition of pages

in the language used to express the document data.

12.2.5 impression

An "impression" is the image (possibly many print-stream pages in

different configurations) imposed onto a single media page.

13. APPENDIX B: Status Codes and Suggested Status Code Messages

This section defines status code enum keywords and values that are

used to provide semantic information on the results of an operation

request. Each operation response MUST include a status code. The

response MAY also contain a status message that provides a short

textual description of the status. The status code is intended for

use by automata, and the status message is intended for the human end

user. Since the status message is an OPTIONAL component of the

operation response, an IPP application (i.e., a browser, GUI, print

driver or gateway) is NOT REQUIRED to examine or display the status

message, since it MAY not be returned to the application.

The prefix of the status keyword defines the class of response as

follows:

"informational" - Request received, continuing process

"successful" - The action was successfully received, understood,

and accepted

"redirection" - Further action must be taken in order to complete

the request

"client-error" - The request contains bad syntax or cannot be

fulfilled

"server-error" - The IPP object failed to fulfill an apparently

valid request

As with type2 enums, IPP status codes are extensible. IPP clients

are NOT REQUIRED to understand the meaning of all registered status

codes, though such understanding is obviously desirable. However,

IPP clients MUST understand the class of any status code, as

indicated by the prefix, and treat any unrecognized response as being

equivalent to the first status code of that class, with the exception

that an unrecognized response MUST NOT be cached. For example, if an

unrecognized status code of "client-error-xxx-yyy" is received by the

client, it can safely assume that there was something wrong with its

request and treat the response as if it had received a "client-

error-bad-request" status code. In such cases, IPP applications

SHOULD present the OPTIONAL message (if present) to the end user

since the message is likely to contain human readable information

which will help to explain the unusual status. The name of the enum

is the suggested status message for US English.

The status code values range from 0x0000 to 0x7FFF. The value ranges

for each status code class are as follows:

"successful" - 0x0000 to 0x00FF

"informational" - 0x0100 to 0x01FF

"redirection" - 0x0200 to 0x02FF

"client-error" - 0x0400 to 0x04FF

"server-error" - 0x0500 to 0x05FF

The top half (128 values) of each range (0x0n40 to 0x0nFF, for n = 0

to 5) is reserved for private use within each status code class.

Values 0x0600 to 0x7FFF are reserved for future assignment and MUST

NOT be used.

13.1 Status Codes

Each status code is described below. Section 13.1.5.9 contains a

table that indicates which status codes apply to which operations.

The Implementer's Guide [ipp-iig] describe the suggested steps for

processing IPP attributes for all operations, including returning

status codes.

13.1.1 Informational

This class of status code indicates a provisional response and is to

be used for informational purposes only.

There are no status codes defined in IPP/1.0 for this class of status

code.

13.1.2 Successful Status Codes

This class of status code indicates that the client's request was

successfully received, understood, and accepted.

13.1.2.1 successful-ok (0x0000)

The request has succeeded and no request attributes were substituted

or ignored. In the case of a response to a create request, the '

successful-ok' status code indicates that the request was

successfully received and validated, and that the Job object has been

created; it does not indicate that the job has been processed. The

transition of the Job object into the 'completed' state is the only

indicator that the job has been printed.

13.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)

The request has succeeded, but some supplied (1) attributes were

ignored or (2) unsupported values were substituted with supported

values or were ignored in order to perform the operation without

rejecting it. Unsupported attributes, attribute syntaxes, or values

MUST be returned in the Unsupported Attributes group of the response

for all operations. There is an exception to this rule for the query

operations: Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes

for the "requested-attributes" operation attribute only. When the

supplied values of the "requested-attributes" operation attribute are

requesting attributes that are not supported, the IPP object MAY, but

is NOT REQUIRED to, return the "requested-attributes" attribute in

the Unsupported Attribute response group (with the unsupported values

only). See section 3.2.1.2.

13.1.2.3 successful-ok-conflicting-attributes (0x0002)

The request has succeeded, but some supplied attribute values

conflicted with the values of other supplied attributes. These

conflicting values were either (1) substituted with (supported)

values or (2) the attributes were removed in order to process the job

without rejecting it. Attributes or values which conflict with other

attributes and have been substituted or ignored MUST be returned in

the Unsupported Attributes group of the response for all operations

as supplied by the client. See section 3.2.1.2.

13.1.3 Redirection Status Codes

This class of status code indicates that further action needs to be

taken to fulfill the request.

There are no status codes defined in IPP/1.0 for this class of status

code.

13.1.4 Client Error Status Codes

This class of status code is intended for cases in which the client

seems to have erred. The IPP object SHOULD return a message

containing an explanation of the error situation and whether it is a

temporary or permanent condition.

13.1.4.1 client-error-bad-request (0x0400)

The request could not be understood by the IPP object due to

malformed syntax (such as the value of a fixed length attribute whose

length does not match the prescribed length for that attribute - see

the Implementer's Guide [ipp-iig] ). The IPP application SHOULD NOT

repeat the request without modifications.

13.1.4.2 client-error-forbidden (0x0401)

The IPP object understood the request, but is refusing to fulfill it.

Additional authentication information or authorization credentials

will not help and the request SHOULD NOT be repeated. This status

code is commonly used when the IPP object does not wish to reveal

exactly why the request has been refused or when no other response is

applicable.

13.1.4.3 client-error-not-authenticated (0x0402)

The request requires user authentication. The IPP client may repeat

the request with suitable authentication information. If the request

already included authentication information, then this status code

indicates that authorization has been refused for those credentials.

If this response contains the same challenge as the prior response,

and the user agent has already attempted authentication at least

once, then the response message may contain relevant diagnostic

information. This status codes reveals more information than

"client-error-forbidden".

13.1.4.4 client-error-not-authorized (0x0403)

The requester is not authorized to perform the request. Additional

authentication information or authorization credentials will not help

and the request SHOULD NOT be repeated. This status code is used

when the IPP object wishes to reveal that the authentication

information is understandable, however, the requester is explicitly

not authorized to perform the request. This status codes reveals

more information than "client-error-forbidden" and "client-error-

not-authenticated".

13.1.4.5 client-error-not-possible (0x0404)

This status code is used when the request is for something that can

not happen. For example, there might be a request to cancel a job

that has already been canceled or aborted by the system. The IPP

client SHOULD NOT repeat the request.

13.1.4.6 client-error-timeout (0x0405)

The client did not produce a request within the time that the IPP

object was prepared to wait. For example, a client issued a Create-

Job operation and then, after a long period of time, issued a Send-

Document operation and this error status code was returned in

response to the Send-Document request (see section 3.3.1). The IPP

object might have been forced to clean up resources that had been

held for the waiting additional Documents. The IPP object was forced

to close the Job since the client took too long. The client SHOULD

NOT repeat the request without modifications.

13.1.4.7 client-error-not-found (0x0406)

The IPP object has not found anything matching the request URI. No

indication is given of whether the condition is temporary or

permanent. For example, a client with an old reference to a Job (a

URI) tries to cancel the Job, however in the mean time the Job might

have been completed and all record of it at the Printer has been

deleted. This status code, 'client-error-not-found' is returned

indicating that the referenced Job can not be found. This error

status code is also used when a client supplies a URI as a reference

to the document data in either a Print-URI or Send-URI operation, but

the document can not be found.

In practice, an IPP application should avoid a not found situation by

first querying and presenting a list of valid Printer URIs and Job

URIs to the end-user.

13.1.4.8 client-error-gone (0x0407)

The requested object is no longer available and no forwarding address

is known. This condition should be considered permanent. Clients

with link editing capabilities should delete references to the

request URI after user approval. If the IPP object does not know or

has no facility to determine, whether or not the condition is

permanent, the status code "client-error-not-found" should be used

instead.

This response is primarily intended to assist the task of maintenance

by notifying the recipient that the resource is intentionally

unavailable and that the IPP object administrator desires that remote

links to that resource be removed. It is not necessary to mark all

permanently unavailable resources as "gone" or to keep the mark for

any length of time -- that is left to the discretion of the IPP

object administrator.

13.1.4.9 client-error-request-entity-too-large (0x0408)

The IPP object is refusing to process a request because the request

entity is larger than the IPP object is willing or able to process.

An IPP Printer returns this status code when it limits the size of

print jobs and it receives a print job that exceeds that limit or

when the attributes are so many that their encoding causes the

request entity to exceed IPP object capacity.

13.1.4.10 client-error-request-value-too-long (0x0409)

The IPP object is refusing to service the request because one or more

of the client-supplied attributes has a variable length value that is

longer than the maximum length specified for that attribute. The IPP

object might not have sufficient resources (memory, buffers, etc.) to

process (even temporarily), interpret, and/or ignore a value larger

than the maximum length. Another use of this error code is when the

IPP object supports the processing of a large value that is less than

the maximum length, but during the processing of the request as a

whole, the object may pass the value onto some other system component

which is not able to accept the large value. For more details, see

the Implementer's Guide [ipp-iig] .

Note: For attribute values that are URIs, this rare condition is

only likely to occur when a client has improperly submitted a request

with long query information (e.g. an IPP application allows an end-

user to enter an invalid URI), when the client has descended into a

URI "black hole" of redirection (e.g., a redirected URI prefix that

points to a suffix of itself), or when the IPP object is under attack

by a client attempting to exploit security holes present in some IPP

objects using fixed-length buffers for reading or manipulating the

Request-URI.

13.1.4.11 client-error-document-format-not-supported (0x040A)

The IPP object is refusing to service the request because the

document data is in a format, as specified in the "document-format"

operation attribute, that is not supported by the Printer object.

This error is returned independent of the client-supplied "ipp-

attribute-fidelity". The Printer object MUST return this status

code, even if there are other attributes that are not supported as

well, since this error is a bigger problem than with Job Template

attributes.

13.1.4.12 client-error-attributes-or-values-not-supported (0x040B)

In a create request, if the Printer object does not support one or

more attributes, attribute syntaxes, or attribute values supplied in

the request and the client supplied the "ipp-attributes-fidelity"

operation attribute with the 'true' value, the Printer object MUST

return this status code. For example, if the request indicates '

iso-a4' media, but that media type is not supported by the Printer

object. Or, if the client supplies an optional attribute and the

attribute itself is not even supported by the Printer. If the "ipp-

attribute-fidelity" attribute is 'false', the Printer MUST ignore or

substitute values for unsupported attributes and values rather than

reject the request and return this status code.

For any operation where a client requests attributes (such as a Get-

Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation), if

the IPP object does not support one or more of the requested

attributes, the IPP object simply ignores the unsupported requested

attributes and processes the request as if they had not been

supplied, rather than returning this status code. In this case, the

IPP object MUST return the 'successful-ok-ignored-or-substituted-

attributes' status code and MAY return the unsupported attributes as

values of the "requested-attributes" in the Unsupported Attributes

Group (see section 13.1.2.2).

13.1.4.13 client-error-uri-scheme-not-supported (0x040C)

The type of the client supplied URI in a Print-URI or a Send-URI

operation is not supported.

13.1.4.14 client-error-charset-not-supported (0x040D)

For any operation, if the IPP Printer does not support the charset

supplied by the client in the "attributes-charset" operation

attribute, the Printer MUST reject the operation and return this

status and any 'text' or 'name' attributes using the 'utf-8' charset

(see Section 3.1.4.1).

13.1.4.15 client-error-conflicting-attributes (0x040E)

The request is rejected because some attribute values conflicted with

the values of other attributes which this specification does not

permit to be substituted or ignored.

13.1.5 Server Error Status Codes

This class of status codes indicates cases in which the IPP object is

aware that it has erred or is incapable of performing the request.

The IPP object SHOULD include a message containing an explanation of

the error situation, and whether it is a temporary or permanent

condition.

13.1.5.1 server-error-internal-error (0x0500)

The IPP object encountered an unexpected condition that prevented it

from fulfilling the request. This error status code differs from

"server-error-temporary-error" in that it implies a more permanent

type of internal error. It also differs from "server-error-device-

error" in that it implies an unexpected condition (unlike a paper-jam

or out-of-toner problem which is undesirable but expected). This

error status code indicates that probably some knowledgeable human

intervention is required.

13.1.5.2 server-error-operation-not-supported (0x0501)

The IPP object does not support the functionality required to fulfill

the request. This is the appropriate response when the IPP object

does not recognize an operation or is not capable of supporting it.

13.1.5.3 server-error-service-unavailable (0x0502)

The IPP object is currently unable to handle the request due to a

temporary overloading or maintenance of the IPP object. The

implication is that this is a temporary condition which will be

alleviated after some delay. If known, the length of the delay may be

indicated in the message. If no delay is given, the IPP application

should handle the response as it would for a "server-error-

temporary-error" response. If the condition is more permanent, the

error status codes "client-error-gone" or "client-error-not-found"

could be used.

13.1.5.4 server-error-version-not-supported (0x0503)

The IPP object does not support, or refuses to support, the IPP

protocol version that was used in the request message. The IPP

object is indicating that it is unable or unwilling to complete the

request using the same version as supplied in the request other than

with this error message. The response should contain a Message

describing why that version is not supported and what other versions

are supported by that IPP object.

A conforming IPP/1.0 client MUST specify the valid version ('1.0') on

each request. A conforming IPP/1.0 object MUST NOT return this

status code to a conforming IPP/1.0 client. An IPP object MUST

return this status code to a non-conforming IPP client. The response

MUST identify in the "version-number" operation attribute the closest

version number that the IPP object does support.

13.1.5.5 server-error-device-error (0x0504)

A printer error, such as a paper jam, occurs while the IPP object

processes a Print or Send operation. The response contains the true

Job Status (the values of the "job-state" and "job-state-reasons"

attributes). Additional information can be returned in the optional

"job-state-message" attribute value or in the OPTIONAL status message

that describes the error in more detail. This error status code is

only returned in situations where the Printer is unable to accept the

create request because of such a device error. For example, if the

Printer is unable to spool, and can only accept one job at a time,

the reason it might reject a create request is that the printer

currently has a paper jam. In many cases however, where the Printer

object can accept the request even though the Printer has some error

condition, the 'successful-ok' status code will be returned. In such

a case, the client would look at the returned Job Object Attributes

or later query the Printer to determine its state and state reasons.

13.1.5.6 server-error-temporary-error (0x0505)

A temporary error such as a buffer full write error, a memory

overflow (i.e. the document data exceeds the memory of the Printer),

or a disk full condition, occurs while the IPP Printer processes an

operation. The client MAY try the unmodified request again at some

later point in time with an expectation that the temporary internal

error condition may have been cleared. Alternatively, as an

implementation option, a Printer object MAY delay the response until

the temporary condition is cleared so that no error is returned.

13.1.5.7 server-error-not-accepting-jobs (0x0506)

A temporary error indicating that the Printer is not currently

accepting jobs, because the administrator has set the value of the

Printer's "printer-is-not-accepting-jobs" attribute to 'false' (by

means outside of IPP/1.0).

13.1.5.8 server-error-busy (0x0507)

A temporary error indicating that the Printer is too busy processing

jobs and/or other requests. The client SHOULD try the unmodified

request again at some later point in time with an expectation that

the temporary busy condition will have been cleared.

13.1.5.9 server-error-job-canceled (0x0508)

An error indicating that the job has been canceled by an operator or

the system while the client was transmitting the data to the IPP

Printer. If a job-id and job-uri had been created, then they are

returned in the Print-Job, Send-Document, or Send-URI response as

usual; otherwise, no job-id and job-uri are returned in the response.

13.2 Status Codes for IPP Operations

PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document

SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and

Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-Job

IPP Operations

IPP Status Keyword PJ PU CJ SD SU V GA GJ C

------------------ -- -- -- -- -- - -- -- -

successful-ok x x x x x x x x x

successful-ok-ignored-or-substituted- x x x x x x x x x

attributes

successful-ok-conflicting-attributes x x x x x x x x x

client-error-bad-request x x x x x x x x x

client-error-forbidden x x x x x x x x x

client-error-not-authenticated x x x x x x x x x

client-error-not-authorized x x x x x x x x x

client-error-not-possible x x x x x x x x x

client-error-timeout x x

client-error-not-found x x x x x x x x x

client-error-gone x x x x x x x x x

client-error-request-entity-too-large x x x x x x x x x

client-error-request-value-too-long x x x x x x x x x

client-error-document-format-not- x x x x x x

supported

client-error-attributes-or-values-not- x x x x x x x x x

supported

client-error-uri-scheme-not-supported x x

client-error-charset-not-supported x x x x x x x x x

client-error-conflicting-attributes x x x x x x x x x

server-error-internal-error x x x x x x x x x

server-error-operation-not-supported x x x x

server-error-service-unavailable x x x x x x x x x

server-error-version-not-supported x x x x x x x x x

server-error-device-error x x x x x

server-error-temporary-error x x x x x

server-error-not-accepting-jobs x x x x

server-error-busy x x x x x x x x x

server-error-job-canceled x x

14. APPENDIX C: "media" keyword values

Standard keyword values are taken from several sources.

Standard values are defined (taken from DPA[ISO10175] and the Printer

MIB[RFC1759]):

'default': The default medium for the output device

'iso-a4-white': Specifies the ISO A4 white medium

'iso-a4-colored': Specifies the ISO A4 colored medium

'iso-a4-transparent' Specifies the ISO A4 transparent medium

'iso-a3-white': Specifies the ISO A3 white medium

'iso-a3-colored': Specifies the ISO A3 colored medium

'iso-a5-white': Specifies the ISO A5 white medium

'iso-a5-colored': Specifies the ISO A5 colored medium

'iso-b4-white': Specifies the ISO B4 white medium

'iso-b4-colored': Specifies the ISO B4 colored medium

'iso-b5-white': Specifies the ISO B5 white medium

'iso-b5-colored': Specifies the ISO B5 colored medium

'jis-b4-white': Specifies the JIS B4 white medium

'jis-b4-colored': Specifies the JIS B4 colored medium

'jis-b5-white': Specifies the JIS B5 white medium

'jis-b5-colored': Specifies the JIS B5 colored medium

The following standard values are defined for North American media:

'na-letter-white': Specifies the North American letter white medium

'na-letter-colored': Specifies the North American letter colored

medium

'na-letter-transparent': Specifies the North American letter

transparent medium

'na-legal-white': Specifies the North American legal white medium

'na-legal-colored': Specifies the North American legal colored

medium

The following standard values are defined for envelopes:

'iso-b4-envelope': Specifies the ISO B4 envelope medium

'iso-b5-envelope': Specifies the ISO B5 envelope medium

'iso-c3-envelope': Specifies the ISO C3 envelope medium

'iso-c4-envelope': Specifies the ISO C4 envelope medium

'iso-c5-envelope': Specifies the ISO C5 envelope medium

'iso-c6-envelope': Specifies the ISO C6 envelope medium

'iso-designated-long-envelope': Specifies the ISO Designated Long

envelope medium

'na-10x13-envelope': Specifies the North American 10x13 envelope

medium

'na-9x12-envelope': Specifies the North American 9x12 envelope

medium

'monarch-envelope': Specifies the Monarch envelope

'na-number-10-envelope': Specifies the North American number 10

business envelope medium

'na-7x9-envelope': Specifies the North American 7x9 inch envelope

'na-9x11-envelope': Specifies the North American 9x11 inch envelope

'na-10x14-envelope': Specifies the North American 10x14 inch

envelope

'na-number-9-envelope': Specifies the North American number 9

business envelope

'na-6x9-envelope': Specifies the North American 6x9 inch envelope

'na-10x15-envelope': Specifies the North American 10x15 inch

envelope

The following standard values are defined for the less commonly used

media (white-only):

'executive-white': Specifies the white executive medium

'folio-white': Specifies the folio white medium

'invoice-white': Specifies the white invoice medium

'ledger-white': Specifies the white ledger medium

'quarto-white': Specified the white quarto medium

'iso-a0-white': Specifies the ISO A0 white medium

'iso-a1-white': Specifies the ISO A1 white medium

'iso-a2-white': Specifies the ISO A2 white medium

'iso-a6-white': Specifies the ISO A6 white medium

'iso-a7-white': Specifies the ISO A7 white medium

'iso-a8-white': Specifies the ISO A8 white medium

'iso-a9-white': Specifies the ISO A9 white medium

'iso-10-white': Specifies the ISO A10 white medium

'iso-b0-white': Specifies the ISO B0 white medium

'iso-b1-white': Specifies the ISO B1 white medium

'iso-b2-white': Specifies the ISO B2 white medium

'iso-b3-white': Specifies the ISO B3 white medium

'iso-b6-white': Specifies the ISO B6 white medium

'iso-b7-white': Specifies the ISO B7 white medium

'iso-b8-white': Specifies the ISO B8 white medium

'iso-b9-white': Specifies the ISO B9 white medium

'iso-b10-white': Specifies the ISO B10 white medium

'jis-b0-white': Specifies the JIS B0 white medium

'jis-b1-white': Specifies the JIS B1 white medium

'jis-b2-white': Specifies the JIS B2 white medium

'jis-b3-white': Specifies the JIS B3 white medium

'jis-b6-white': Specifies the JIS B6 white medium

'jis-b7-white': Specifies the JIS B7 white medium

'jis-b8-white': Specifies the JIS B8 white medium

'jis-b9-white': Specifies the JIS B9 white medium

'jis-b10-white': Specifies the JIS B10 white medium

The following standard values are defined for engineering media:

'a': Specifies the engineering A size medium

'b': Specifies the engineering B size medium

'c': Specifies the engineering C size medium

'd': Specifies the engineering D size medium

'e': Specifies the engineering E size medium

The following standard values are defined for input-trays (from ISO

DPA and the Printer MIB):

'top': The top input tray in the printer.

'middle': The middle input tray in the printer.

'bottom': The bottom input tray in the printer.

'envelope': The envelope input tray in the printer.

'manual': The manual feed input tray in the printer.

'large-capacity': The large capacity input tray in the printer.

'main': The main input tray

'side': The side input tray

The following standard values are defined for media sizes (from ISO

DPA):

'iso-a0': Specifies the ISO A0 size: 841 mm by 1189 mm as defined

in ISO 216

'iso-a1': Specifies the ISO A1 size: 594 mm by 841 mm as defined in

ISO 216

'iso-a2': Specifies the ISO A2 size: 420 mm by 594 mm as defined in

ISO 216

'iso-a3': Specifies the ISO A3 size: 297 mm by 420 mm as defined in

ISO 216

'iso-a4': Specifies the ISO A4 size: 210 mm by 297 mm as defined in

ISO 216

'iso-a5': Specifies the ISO A5 size: 148 mm by 210 mm as defined in

ISO 216

'iso-a6': Specifies the ISO A6 size: 105 mm by 148 mm as defined in

ISO 216

'iso-a7': Specifies the ISO A7 size: 74 mm by 105 mm as defined in

ISO 216

'iso-a8': Specifies the ISO A8 size: 52 mm by 74 mm as defined in

ISO 216

'iso-a9': Specifies the ISO A9 size: 37 mm by 52 mm as defined in

ISO 216

'iso-a10': Specifies the ISO A10 size: 26 mm by 37 mm as defined in

ISO 216

'iso-b0': Specifies the ISO B0 size: 1000 mm by 1414 mm as defined

in ISO 216

'iso-b1': Specifies the ISO B1 size: 707 mm by 1000 mm as defined

in ISO 216

'iso-b2': Specifies the ISO B2 size: 500 mm by 707 mm as defined in

ISO 216

'iso-b3': Specifies the ISO B3 size: 353 mm by 500 mm as defined in

ISO 216

'iso-b4': Specifies the ISO B4 size: 250 mm by 353 mm as defined in

ISO 216

'iso-b5': Specifies the ISO B5 size: 176 mm by 250 mm as defined in

ISO 216

'iso-b6': Specifies the ISO B6 size: 125 mm by 176 mm as defined in

ISO 216

'iso-b7': Specifies the ISO B7 size: 88 mm by 125 mm as defined in

ISO 216

'iso-b8': Specifies the ISO B8 size: 62 mm by 88 mm as defined in

ISO 216

'iso-b9': Specifies the ISO B9 size: 44 mm by 62 mm as defined in

ISO 216

'iso-b10': Specifies the ISO B10 size: 31 mm by 44 mm as defined in

ISO 216

'na-letter': Specifies the North American letter size: 8.5 inches by

11 inches

'na-legal': Specifies the North American legal size: 8.5 inches by

14 inches

'executive': Specifies the executive size (7.25 X 10.5 in)

'folio': Specifies the folio size (8.5 X 13 in)

'invoice': Specifies the invoice size (5.5 X 8.5 in)

'ledger': Specifies the ledger size (11 X 17 in)

'quarto': Specifies the quarto size (8.5 X 10.83 in)

'iso-c3': Specifies the ISO C3 size: 324 mm by 458 mm as defined in

ISO 269

'iso-c4': Specifies the ISO C4 size: 229 mm by 324 mm as defined in

ISO 269

'iso-c5': Specifies the ISO C5 size: 162 mm by 229 mm as defined in

ISO 269

'iso-c6': Specifies the ISO C6 size: 114 mm by 162 mm as defined in

ISO 269

'iso-designated-long': Specifies the ISO Designated Long size: 110

mm by 220 mm as defined in ISO 269

'na-10x13-envelope': Specifies the North American 10x13 size: 10

inches by 13 inches

'na-9x12-envelope': Specifies the North American 9x12 size: 9

inches by 12 inches

'na-number-10-envelope': Specifies the North American number 10

business envelope size: 4.125 inches by 9.5 inches

'na-7x9-envelope': Specifies the North American 7x9 inch envelope

size

'na-9x11-envelope': Specifies the North American 9x11 inch envelope

size

'na-10x14-envelope': Specifies the North American 10x14 inch

envelope size

'na-number-9-envelope': Specifies the North American number 9

business envelope size

'na-6x9-envelope': Specifies the North American 6x9 envelope size

'na-10x15-envelope': Specifies the North American 10x15 envelope

size

'monarch-envelope': Specifies the Monarch envelope size (3.87 x 7.5

in)

'jis-b0': Specifies the JIS B0 size: 1030mm x 1456mm

'jis-b1': Specifies the JIS B1 size: 728mm x 1030mm

'jis-b2': Specifies the JIS B2 size: 515mm x 728mm

'jis-b3': Specifies the JIS B3 size: 364mm x 515mm

'jis-b4': Specifies the JIS B4 size: 257mm x 364mm

'jis-b5': Specifies the JIS B5 size: 182mm x 257mm

'jis-b6': Specifies the JIS B6 size: 128mm x 182mm

'jis-b7': Specifies the JIS B7 size: 91mm x 128mm

'jis-b8': Specifies the JIS B8 size: 64mm x 91mm

'jis-b9': Specifies the JIS B9 size: 45mm x 64mm

'jis-b10': Specifies the JIS B10 size: 32mm x 45mm

15. APPENDIX D: Processing IPP Attributes

When submitting a print job to a Printer object, the IPP model allows

a client to supply operation and Job Template attributes along with

the document data. These Job Template attributes in the create

request affect the rendering, production and finishing of the

documents in the job. Similar types of instructions may also be

contained in the document to be printed, that is, embedded within the

print data itself. In addition, the Printer has a set of attributes

that describe what rendering and finishing options which are

supported by that Printer. This model, which allows for flexibility

and power, also introduces the potential that at job submission time,

these client-supplied attributes may conflict with either:

- what the implementation is capable of realizing (i.e., what the

Printer supports), as well as

- the instructions embedded within the print data itself.

The following sections describe how these two types of conflicts are

handled in the IPP model.

15.1 Fidelity

If there is a conflict between what the client requests and what a

Printer object supports, the client may request one of two possible

conflict handling mechanisms:

1) either reject the job since the job can not be processed exactly

as specified, or

2) allow the Printer to make any changes necessary to proceed with

processing the Job the best it can.

In the first case the client is indicating to the Printer object:

"Print the job exactly as specified with no exceptions, and if that

can't be done, don't even bother printing the job at all." In the

second case, the client is indicating to the Printer object: "It is

more important to make sure the job is printed rather than be

processed exactly as specified; just make sure the job is printed

even if client supplied attributes need to be changed or ignored."

The IPP model accounts for this situation by introducing an "ipp-

attribute-fidelity" attribute.

In a create request, "ipp-attribute-fidelity" is a boolean operation

attribute that is OPTIONALLY supplied by the client. The value '

true' indicates that total fidelity to client supplied Job Template

attributes and values is required. The client is requesting that the

Job be printed exactly as specified, and if that is not possible then

the job MUST be rejected rather than processed incorrectly. The

value 'false' indicates that a reasonable attempt to print the Job is

acceptable. If a Printer does not support some of the client

supplied Job Template attributes or values, the Printer MUST ignore

them or substitute any supported value for unsupported values,

respectively. The Printer may choose to substitute the default value

associated with that attribute, or use some other supported value

that is similar to the unsupported requested value. For example, if

a client supplies a "media" value of 'na-letter', the Printer may

choose to substitute 'iso-a4' rather than a default value of '

envelope'. If the client does not supply the "ipp-attribute-fidelity"

attribute, the Printer assumes a value of 'false'.

Each Printer implementation MUST support both types of "fidelity"

printing (that is whether the client supplies a value of 'true' or '

false'):

- If the client supplies 'false' or does not supply the attribute,

the Printer object MUST always accept the request by ignoring

unsupported Job Template attributes and by substituting

unsupported values of supported Job Template attributes with

supported values.

- If the client supplies 'true', the Printer object MUST reject the

request if the client supplies unsupported Job Template

attributes.

Since a client can always query a Printer to find out exactly what is

and is not supported, "ipp-attribute-fidelity" set to 'false' is

useful when:

1) The End-User uses a command line interface to request attributes

that might not be supported.

2) In a GUI context, if the End User expects the job might be moved

to another printer and prefers a sub-optimal result to nothing

at all.

3) The End User just wants something reasonable in lieu of nothing

at all.

15.2 Page Description Language (PDL) Override

If there is a conflict between the value of an IPP Job Template

attribute and a corresponding instruction in the document data, the

value of the IPP attribute SHOULD take precedence over the document

instruction. Consider the case where a previously formatted file of

document data is sent to an IPP Printer. In this case, if the client

supplies any attributes at job submission time, the client desires

that those attributes override the embedded instructions. Consider

the case were a previously formatted document has embedded in it

commands to load 'iso-a4' media. However, the document is passed to

an end user that only has access to a printer with 'na-letter' media

loaded. That end user most likely wants to submit that document to

an IPP Printer with the "media" Job Template attribute set to 'na-

letter'. The job submission attribute should take precedence over

the embedded PDL instruction. However, until companies that supply

document data interpreters allow a way for external IPP attributes to

take precedence over embedded job production instructions, a Printer

might not be able to support the semantics that IPP attributes

override the embedded instructions.

The IPP model accounts for this situation by introducing a "pdl-

override-supported" attribute that describes the Printer objects

capabilities to override instructions embedded in the PDL data

stream. The value of the "pdl-override-supported" attribute is

configured by means outside IPP/1.0.

This REQUIRED Printer attribute takes on the following values:

- 'attempted': This value indicates that the Printer object

attempts to make the IPP attribute values take precedence over

embedded instructions in the document data, however there is no

guarantee.

- 'not-attempted': This value indicates that the Printer object

makes no attempt to make the IPP attribute values take precedence

over embedded instructions in the document data.

At job processing time, an implementation that supports the value of

'attempted' might do one of several different actions:

1) Generate an output device specific command sequence to realize

the feature represented by the IPP attribute value.

2) Parse the document data itself and replace the conflicting

embedded instruction with a new embedded instruction that

matches the intent of the IPP attribute value.

3) Indicate to the Printer that external supplied attributes take

precedence over embedded instructions and then pass the external

IPP attribute values to the document data interpreter.

4) Anything else that allows for the semantics that IPP attributes

override embedded document data instructions.

Since 'attempted' does not offer any type of guarantee, even though a

given Printer object might not do a very "good" job of attempting to

ensure that IPP attributes take a higher precedence over instructions

embedded in the document data, it would still be a conforming

implementation.

At job processing time, an implementation that supports the value of

'not-attempted' might do one of the following actions:

1) Simply pre-pend the document data with the PDL instruction that

corresponds to the client-supplied PDL attribute, such that if

the document data also has the same PDL instruction, it will

override what the Printer object pre-pended. In other words,

this implementation is using the same implementation semantics

for the client-supplied IPP attributes as for the Printer object

defaults.

2) Parse the document data and replace the conflicting embedded

instruction with a new embedded instruction that approximates,

but does not match, the semantic intent of the IPP attribute

value.

Note: The "ipp-attribute-fidelity" attribute applies to the

Printer's ability to either accept or reject other unsupported Job

Template attributes. In other words, if "ipp-attribute-fidelity" is

set to 'true', a Job is accepted if and only if the client supplied

Job Template attributes and values are supported by the Printer.

Whether these attributes actually affect the processing of the Job

when the document data contains embedded instructions depends on the

ability of the Printer to override the instructions embedded in the

document data with the semantics of the IPP attributes. If the

document data attributes can be overridden ("pdl-override-supported"

set to 'attempted'), the Printer makes an attempt to use the IPP

attributes when processing the Job. If the document data attributes

can not be overridden ("pdl-override-supported" set to 'not-

attempted'), the Printer makes no attempt to override the embedded

document data instructions with the IPP attributes when processing

the Job, and hence, the IPP attributes may fail to affect the Job

processing and output when the corresponding instruction is embedded

in the document data.

15.3 Using Job Template Attributes During Document Processing.

The Printer object uses some of the Job object's Job Template

attributes during the processing of the document data associated with

that job. These include, but are not limited to, "orientation",

"number-up", "sides", "media", and "copies". The processing of each

document in a Job Object MUST follow the steps below. These steps are

intended only to identify when and how attributes are to be used in

processing document data and any alternative steps that accomplishes

the same effect can be used to implement this specification.

1. Using the client supplied "document-format" attribute or some

form of document format detection algorithm (if the value of

"document- format" is not specific enough), determine whether or

not the document data has already been formatted for printing.

If the document data has been formatted, then go to step 2.

Otherwise, the document data MUST be formatted. The formatting

detection algorithm is implementation defined and is not

specified by this specification. The formatting of the document

data uses the "orientation-requested" attribute to determine how

the formatted print data should be placed on a print-stream

page, see section 4.2.10 for the details.

2. The document data is in the form of a print-stream in a known

media type. The "page-ranges" attribute is used to select, as

specified in section 4.2.7, a sub-sequence of the pages in the

print-stream that are to be processed and images.

3. The input to this step is a sequence of print-stream pages. This

step is controlled by the "number-up" attribute. If the value of

"number-up" is N, then during the processing of the print-stream

pages, each N print-stream pages are positioned, as specified in

section 4.2.9, to create a single impression. If a given

document does not have N more print-stream pages, then the

completion of the impression is controlled by the "multiple-

document-handling" attribute as described in section 4.2.4; when

the value of this attribute is 'single-document' or 'single-

document-new-sheet', the print-stream pages of document data

from subsequent documents is used to complete the impression.

The size(scaling), position(translation) and rotation of the

print-stream pages on the impression is implementation defined.

Note that during this process the print-stream pages may be

rendered to a form suitable for placing on the impression; this

rendering is controlled by the values of the "printer-

resolution" and "print- quality" attributes as described in

sections 4.2.12 and 4.2.13. In the case N=1, the impression is

nearly the same as the print-stream page; the differences would

only be in the size, position and rotation of the print-stream

page and/or any decoration, such as a frame to the page, that is

added by the implementation.

4. The collection of impressions is placed, in sequence, onto sides

of the media sheets. This placement is controlled by the "sides"

attribute and the orientation of the print-stream page, as

described in section 4.2.8. The orientation of the print-stream

pages affects the orientation of the impression; for example, if

"number-up" equals 2, then, typically, two portrait print-stream

pages become one landscape impression. Note that the placement

of impressions onto media sheets is also controlled by the

"multiple-document-handling" attribute as described in section

4.2.4.

5. The "copies" and "multiple-document-handling" attributes are

used to determine how many copies of each media instance are

created and in what order. See sections 4.2.5 and 4.2.4 for the

details.

6. When the correct number of copies are created, the media

instances are finished according to the values of the

"finishings" attribute as described in 4.2.6. Note that

sometimes finishing operations may require manual intervention

to perform the finishing operations on the copies, especially

uncollated copies. This specification allows any or all of the

processing steps to be performed automatically or manually at

the discretion of the Printer object.

16. APPENDIX E: Generic Directory Schema

This section defines a generic schema for an entry in a directory

service. A directory service is a means by which service users can

locate service providers. In IPP environments, this means that IPP

Printers can be registered (either automatically or with the help of

an administrator) as entries of type printer in the directory using

an implementation specific mechanism such as entry attributes, entry

type fields, specific branches, etc. IPP clients can search or

browse for entries of type printer. Clients use the directory

service to find entries based on naming, organizational contexts, or

filtered searches on attribute values of entries. For example, a

client can find all printers in the "Local Department" context.

Authentication and authorization are also often part of a directory

service so that an administrator can place limits on end users so

that they are only allowed to find entries to which they have certain

access rights. IPP itself does not require any specific directory

service protocol or provider.

Note: Some directory implementations allow for the notion of

"aliasing". That is, one directory entry object can appear as

multiple directory entry object with different names for each object.

In each case, each alias refers to the same directory entry object

which refers to a single IPP Printer object.

The generic schema is a subset of IPP Printer Job Template and

Printer Description attributes (sections 4.2 and 4.4). These

attributes are identified as either RECOMMENDED or OPTIONAL for the

directory entry itself. This conformance labeling is NOT the same

conformance labeling applied to the attributes of IPP Printers

objects. The conformance labeling in this Appendix is intended to

apply to directory templates and to IPP Printer implementations that

subscribe by adding one or more entries to a directory. RECOMMENDED

attributes SHOULD be associated with each directory entry. OPTIONAL

attributes MAY be associated with the directory entry (if known or

supported). In addition, all directory entry attributes SHOULD

reflect the current attribute values for the corresponding Printer

object.

The names of attributes in directory schema and entries SHOULD be the

same as the IPP Printer attribute names as shown.

In order to bridge between the directory service and the IPP Printer

object, one of the RECOMMENDED directory entry attributes is the

Printer object's "printer-uri-supported" attribute. The IPP client

queries the "printer-uri-supported" attribute in the directory entry

and then addresses the IPP Printer object using one of its URIs. The

"uri-security-supported" attribute identifies the protocol (if any)

used to secure a channel.

The following attributes define the generic schema for directory

entries of type PRINTER:

printer-uri-supported RECOMMENDED Section 4.4.1

uri-security-supported RECOMMENDED Section 4.4.2

printer-name RECOMMENDED Section 4.4.3

printer-location RECOMMENDED Section 4.4.4

printer-info OPTIONAL Section 4.4.5

printer-more-info OPTIONAL Section 4.4.6

printer-make-and-model RECOMMENDED Section 4.4.8

charset-supported OPTIONAL Section 4.4.15

generated-natural-language-

supported OPTIONAL Section 4.4.17

document-format-supported RECOMMENDED Section 4.4.19

color-supported RECOMMENDED Section 4.4.23

finishings-supported OPTIONAL Section 4.2.6

number-up-supported OPTIONAL Section 4.2.7

sides-supported RECOMMENDED Section 4.2.8

media-supported RECOMMENDED Section 4.2.11

printer-resolution-supported OPTIONAL Section 4.2.12

print-quality-supported OPTIONAL Section 4.2.13

17. APPENDIX F: Change History for the IPP Model and Semantics document

The following substantive changes and major clarifications have been

made to this document from the June 30, 1998 version based on the

interoperability testing that took place September 23-25 1998 and

subsequent mailing list and meeting discussions. They are listed in

the order of occurrence in the document. These changes are the ones

that might affect implementations. Clarifications that are unlikely

to affect implementations are not listed. The issue numbers refer to

the IPP Issues List which is available in the following directory:

ftp://ftp.pwg.org/pub/pwg/ipp/approved-clarifications/

Section Description

global Replaced TLS references with SSL3 references as agreed with

our Area Director on 11/12/1998.

global Removed the indications that some of these IPP documents

are informational, since the intent is now to publish all

IPP/1.0 documents as informational as agreed with our Area

Director on 11/12/1998.

3.1.2, Clarify that the IPP object SHOULD NOT validate the

16.3.3 range of the request-id being 1 to 2**31-1, but accepts

[now ipp- and returns any value. Clients MUST still keep in the

iig] range 1 to 2**31 though. If the request is terminated

before the complete "request-id" is received, the IPP

object rejects the request and returns a response with a

"request-id" of 0 (Issue 1.36).

3.1.4.1, Clarified that when a client submits a request in a

13.1.4.14 charset that is not supported, the IPP object SHOULD

return any 'text' or 'name' attributes in the 'utf-8'

charset, if it returns any, since clients and IPP

objects MUST support 'utf-8'. (Issue 1.19)

3.1.4.1 Clarified Section 3.1.4.1 Request Operation Attributes

that a client MAY use the attribute level natural

language override (text/nameWithLanguage) redundantly in

a request. (Issue 1.46)

3.1.4.2 Clarified Section 3.1.4.2 Response Operation Attributes

that an IPP object MAY use the attribute level natural

language override (text/nameWithLanguage) redundantly in

a response. (Issue 1.46)

3.1.6 Clarified section 3.1.6: If the Printer object supports

the "status-message" operation attribute, it NEED NOT

return a status message for the following error status

codes: 'client-error-bad-request', 'client-error-

charset-not-supported', 'server-error-internal-error',

'server-error-operation-not-supported', and 'server-

error-version-not-supported'.

3.2.1.1 Clarified that if a client is not supplying any Job

Template attributes in a request, the client SHOULD omit

Group 2 rather than sending an empty group. However, a

Printer object MUST be able to accept an empty group.

This makes [RFC2566] agree with [RFC2565]. (Issue 1.16)

3.2.1.2, Clarified that if an IPP object is not returning any

3.2.5.2, Unsupported Attributes in a response, the IPP object

3.2.6.2, SHOULD omit Group 2 rather than sending an empty group.

3.3.1.2, However, a client MUST be able to accept an empty group.

3.3.3.2, This makes [RFC2566] agree with [RFC2565]. (Issue 1.17)

3.3.4.2

3.2.1.2, Clarified that an IPP object MUST treat an unsupported

13.1.2.2, attribute syntax supplied in a request in the same way

13.1.4.12 as an unsupported value. The IPP object MUST return the

attribute, the attribute syntax, and the value in the

Unsupported Attributes group. (Issue 1.26)

3.2.5.2, Clarified for Get-Printer-Attributes, Get-Jobs, and Get-

3.2.6.2, Job-Attributes that an IPP object MUST return

3.3.4.2, 'successful-ok-ignored-or-substituted-attributes' (0x1),

13.1.2.1, rather than 'successful-ok' (0x0), when a client

13.1.2.2, supplies unsupported attributes as values of the

13.1.4.12 'requested-attributes' operation attribute. (Issue

1.24)

Also clarified that the response NEED NOT contain the

"requested-attributes" operation attribute with any

supplied values (attribute keywords) that were requested

by the client but are not supported by the IPP object.

(Issue 1.18)

3.2.6.2 Deleted the job-level natural language override (NLO)

4.1.1.2 from Section 3.2.6.2 Get-Jobs Response so that all

4.3.24 operation responses are the same with respect to NLO.

(Issue 1.47)

3.3.1 Clarified that an IPP Printer that supports the Create-

Job operation MUST handle the situation when a client

does not supply Send-Document or Send-URI operations

within a one- to four-minute time period. Also

clarified that a client MUST send documents in a multi-

document job without undue or unbounded delay. (Issue

1.28)

3.3.3 Clarified that the IPP object MUST reject a Cancel-Job

request if the job is in 'completed', 'canceled', or

'aborted' job states. (Issue 1.12)

4.1.2.3 Added this new sub-section: it specifies that

nameWithoutLanguage plus the implicit natural language

matches nameWithLanguage, if the values and natural

languages are the same. Also added that keyword never

matches nameWithLanguage or nameWithoutLanguage.

Clarified that if both have countries, that the

countries SHOULD match as well. If either do not, then

the country field SHOULD be ignored. (Issues 1.33 and

1.34)

4.1.5 Clarified regarding the case-insensitivity of URLs to

refer only to the RFCs that define them. (Issue 1.10)

4.1.11 Clarified that 'boolean' is not a full-sized integer.

(Issue 1.38)

4.1.15 Clarified that 'resolution' is not three full-sized

integers. (Issue 1.20)

4.2.* Clarified that standard values are keywords or enums,

not names. (Issue 1.49).

4.2.4 Added the 'single-document-new-sheet' value to Section

4.2.4 multiple-document-handling. (Issue 1.54)

4.4.18, Clarified that the "document-format-default" and

4.4.19 "document-format-supported" Printer Description

attributes are REQUIRED to agree with the table. (Issue

1.4)

4.4.21 Changed "queued-job-count" from OPTIONAL to RECOMMENDED.

(Issue 1.14)

4.4.28 Clarified that the implementation supplied value for the

"multiple-operation-time-out" attribute SHOULD be

between 30 and 240 seconds, though the implementation

MAY allow the administrator to set values, and MAY allow

values outside this range. (Issue 1.28)

5.1, Clarified Client Conformance that if a client supports

5.2.5 an attribute of 'text' attribute syntax, that it MUST

support both the textWithoutLanguage and the

textWithLanguage forms. Same for 'name' attribute

syntax. Same for an IPP object (Issue 1.48)

6.5, Added new section to allow Attribute Groups to be

12.8 registered as extensions for being passed in operation

requests and responses. (Issue 1.25)

7. Updated the table of text and name attributes to agree

with Section 4.2.

8.5 Added a new section RECOMMENDING that the Get-Jobs

SHOULD return non-IPP jobs whether or not assigning them

a job-id and job-uri. Also RECOMMENDED generating, if

possible, job-id and job-uri and supporting other IPP

operations on foreign jobs as an implementer option.

(Issue 1.32)

9. Updated document references.

13.1.4.14 Clarified 'client-error-charset-not-supported' that

'utf-8' must be used for any 'text' or 'name' attributes

returned in the error response (Issue 1.19).

13.1.5.9 Added a new error code 'server-error-job-canceled'

(0x0508) to be returned if a job is canceled by another

client or aborted by the IPP object while the first

client is still sending the document data. (Issue 1.29)

15.3, Moved these sections recommending operation processing

15.4 steps to the new Implementer's Guide (informational).

There indicated that all of the error checks are not

required, so an IPP object MAY be forgiving and accept

non-conforming requests. However, a conforming client

MUST supply requests that would pass all of the error

checks indicated. (Issue 1.21)

16 Changed directory schema attributes from REQUIRED to

RECOMMENDED. Changed some of the OPTIONAL to

RECOMMENDED to agree with the SLP template. Changed the

"charset-supported" and "natural-language-supported"

from REQUIRED to OPTIONAL. Recommended that the names

be the same in a directory entry as the IPP attribute

names. (Issue 1.53)

18. Full Copyright Statement

Copyright (C) The Internet Society (1999). All Rights Reserved.

This document and translations of it may be copied and furnished to

others, and derivative works that comment on or otherwise explain it

or assist in its implementation may be prepared, copied, published

and distributed, in whole or in part, without restriction of any

kind, provided that the above copyright notice and this paragraph are

included on all such copies and derivative works. However, this

document itself may not be modified in any way, such as by removing

the copyright notice or references to the Internet Society or other

Internet organizations, except as needed for the purpose of

developing Internet standards in which case the procedures for

copyrights defined in the Internet Standards process must be

followed, or as required to translate it into languages other than

English.

The limited permissions granted above are perpetual and will not be

revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an

"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING

TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING

BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION

HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF

MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

 
 
 
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