XML-Schema的DTD描述
XML-Schema的DTD描述 转的，相当不错！
<!ENTITY % datatypes '(entity | entities | enumeration | id | idref | idrefs | nmtoken | nmtokens | notation | string | bin.base64 | bin.hex | boolean | char | date | dateTime | dateTime.tz | fixed.14.4 | float | int | number | time | time.tz | i1 | i2 | i4 | r4 | r8 | ui1 | ui2 | ui4 | uri | uuid)'
>
<!-- *** 数据类型 **** -->
<!ELEMENT datatype (description)*>
<!ATTLIST datatype
dt:type %datatypes; #IMPLIED
xmlns:dt CDATA #FIXED 'urn:schemas-microsoft-com:datatypes'
>
<!-- ***** 描述 ***** -->
<!ELEMENT description (#PCDATA) >
<!-- **** 元素引用 ***** -->
<!--附加限制： maxOccurs 必须是 1 or '*' -->
<!ELEMENT element (description)* >
<!ATTLIST element
type IDREF #REQUIRED
minOccurs CDATA #IMPLIED
maxOccurs CDATA #IMPLIED
>
<!-- **** 属性引用 ***** -->
<!ELEMENT attribute (description)* >
<!ATTLIST attribute
type IDREF #REQUIRED
default CDATA #IMPLIED
required (yes | no) 'no'
>
<!-- **** 属性定义 ***** -->
<!ELEMENT AttributeType (datatype | description)* >
<!ATTLIST AttributeType
name ID #REQUIRED
default CDATA #IMPLIED
dt:type %datatypes; #IMPLIED
dt:values CDATA #IMPLIED
required (yes | no) #IMPLIED
xmlns:dt CDATA #FIXED 'urn:schemas-microsoft-com:datatypes'
>
<!-- **** 元素定义 ***** -->
<!ELEMENT ElementType (datatype | description | AttributeType | attribute | element | group)* >
<!ATTLIST ElementType
name ID #REQUIRED
model (open | closed) #IMPLIED
content (empty | textOnly | eltOnly | mixed) #IMPLIED
order (one | seq | many) #IMPLIED
dt:type %datatypes; #IMPLIED
dt:values CDATA #IMPLIED
required (yes | no) #IMPLIED
xmlns:dt CDATA #FIXED 'urn:schemas-microsoft-com:datatypes'
>
<!-- **** 分组 ***** -->
<!ELEMENT group (group | element | description)*>
<!ATTLIST group
minOccurs CDATA #IMPLIED
maxOccurs CDATA #IMPLIED
order (one | seq | many) #IMPLIED
>
<!-- **** Schema ***** -->
<!ELEMENT Schema (AttributeType | ElementType | description )* >
<!ATTLIST Schema
name CDATA #IMPLIED
xmlns:dt CDATA #FIXED 'urn:schemas-microsoft-com:datatypes'
>