Internationalization Tag Set (ITS)

1.1 Background: Motivation for ITS

Content or software that is authored in one language (i.e. source language) is often made available in additional languages. This is done through a process called localization, where the original material is translated and adapted to the target audience.

From the viewpoints of feasibility, cost, and efficiency, it is important that the original material should be suitable for localization. This is achieved by appropriate design and development, and the corresponding process is referred to as internationalization. For a detailed explanation of the terms "localization" and "internationalization", see [l10n i18n].

The increasing usage of XML as a medium for documentation-related content (e.g. DocBook [DocBook], a format for writing structured documentation, well suited to computer hardware and software manuals) and software-related content (e.g. the eXtensible User Interface Language [XUL]) creates challenges and opportunities in the domain of XML internationalization and localization.

The following examples sketch one of the issues that currently hinder efficient XML-related localization: the lack of a standard, declarative mechanism which identifies which parts of an XML instance need to be translated (the text in bold face shows the parts that need to be localized). Tools often cannot automatically do this identification.

<Manual>
 <Info>
  <PhaseCode>Review Level</PhaseCode>
  <FormNo>8U81-GS-52C</FormNo>
  <Name>Owner's Manual</Name>
  ...
 </Info>
 <Section id="0" title="#Introduction#">
  <Ltitle id="005" title="#ZOOM#">
   <Mtitle id="00501" title="Getting started" option="no" cols="1">
    <MultiCol cols="1">
     <Text>Some text to localize</Text>
     ...
    </Multicol>
   </Mtitle>
  </Ltitle>...
</Manual>

<dialogue xml:lang="en-gb">
 <rsrc id="123">
  <component id="456" type="image">
   <data type="text">images/cancel.gif</data>
   <data type="coordinates">12,20,50,14</data>
  </component>
  <component id="789" type="caption">
   <data type="text">Cancel</data>
   <data type="coordinates">12,34,50,14</data>
  </component>
 </rsrc>
</dialogue>

<resources>
 <section id="Homepage">
  <arguments>
   <string>page</string>
   <string>childlist</string>
  </arguments>
  <variables>
   <string>POLICY</string>
   <string>Corporate Policy</string>
  </variables>
  <keyvalue_pairs>
   <string>Page</string>
   <string>ABC Corporation - Policy Repository</string>
   <string>Footer_Last</string>
   <string>Pages</string>
   <string>bgColor</string>
   <string>NavajoWhite</string>
   <string>title</string>
   <string>List of Available Policies</string>
  </keyvalue_pairs>
 </section>
</resources>

1.2 Out of Scope

The data categories and their implementation as a schema does not address document-external mechanisms or data formats for describing localization-relevant information over and above what is appropriate for inclusion in the format itself. Such mechanisms and data formats, also sometimes called XML Localization Properties, are out of the scope of this document. However, this document specifies a methodology how localization properties and information about internationalization and localization can be applied to various places in schemas and instance documents. See Section 4: Selection of ITS information.

1.3 Important Design Principles

Abstraction via data categories: ITS defines data categories as a description of information for internationalization and localization of XML schemas and documents. This description is independent of its implementation e.g. using an element or attribute. See Section 3.3: Data category for a definition of the term data categories, Section 5: Description of Data Categories for the definition of the various ITS data categories, and Section 7: Markup Declarations for the data category implementations.

Selection mechanisms, here exemplified by the translatability data category: Content authors need a simple way to express whether the content of an element or attribute should be translated or not, e.g. a translate attribute. On the other hand, for translations of large document sets based on the same schema, a specification of defaults for translatability and exceptions from the defaults is important (e.g. all p elements should be translated, but not p elements inside of an index element). This specification responds to these requirements by introducing mechanisms for specifying ITS information in XML documents or schemas, see Section 4: Selection of ITS information. This method also provides a means for specifying ITS information for attributes (a task for which no standard means yet exists). The ITS mechanisms for selection are:

• useable for both XML schemas and XML instances

• useable local (at the XML node to which it pertains) or globally (not at the XML node to which it pertains)

Extensibility: It may be useful or necessary to extend the set of information available for internationalization or localization purposes beyond what is provided by ITS. This specification does not define a general extension mechanism, since ordinary XML mechanisms (e.g. XML Namespaces [XML Names]) may be used.

Ease of integration:

• ITS follows the example from section 4 of [XLink 1.1], by providing mostly global attributes for the implementation of ITS data categories. Avoiding elements for ITS purposes as much as possible ensures ease of integration into existing markup schemes, see section 3.14 in [ITS REQ]. Only for some requirements do additional child elements have to be used, see for example Section 5.6: Ruby.

• ITS has no dependency on technologies which are yet to be developed

• ITS fits with existing work in the W3C architecture (e.g. use of XPath [XPath 1.0] as a selection mechanism)

1.4 Development of this Specification

This specification has been developed using the ODD (One Document Does it all) language of the Text Encoding Initiative ([TEI]). This is a literate programming language for writing XML schemas, with three characteristics:

1. The element and attribute set is specified using an XML vocabulary which includes support for macros (like DTD entities, or schema patterns), a hierarchical class system for attributes and elements, and creation of modules.

2. The content models for elements and attributes is written using embedded RELAX NG XML notation.

3. Documentation for elements, attributes, value lists etc is written inline, along with examples and other supporting material.

XSLT transform are provided by the TEI to extract documentation in HTML, XSL FO or LaTeX forms, and to generate RELAX NG documents and DTD. From the RELAX NG documents, James Clark's trang can be used to create XML Schema documents.

3.1 Notation

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC 2119].

The namespace URI that must be used by implementations of this specification is:

http://www.w3.org/2005/11/its

The namespace prefix used in this specification for this URI is "its". It is recommended that implementations of this specification use this prefix.

In addition, the following namespaces are used in this document:

• http://www.w3.org/2001/XMLSchema for the XML Schema namespace, here used with the prefix "xs"

• http://relaxng.org/ns/structure/1.0 for the RELAX NG namespace, here used with the prefix "rng"

3.2 Schema Language and Schema Annotation

[Definition: Schema language refers in this specification to XML DTD, XML Schema or RELAX NG.]

[Definition: Schema annotation is a schema language specific means to provide information about element, attribute, type etc. declarations. This information is not used by the schema processor, but for external, validation independent applications.]

3.3 Data category

[Definition: ITS defines data category as an abstract concept for a particular type of information for internationalization and localization of XML schemas and documents.] The concept of a data category is independent of its implementation in an XML environment (e.g. using an element or attribute).

For each data category, ITS distinguishes between the following:

• the prose description, see Section 5: Description of Data Categories

• schema language independent formalization, see Section 7: Markup Declarations

• schema language specific implementations, see Appendix A: Schemas for ITS

3.4 Selection

[Definition: selection encompasses mechanisms to specify to what parts of an XML document or schema an ITS data category and its values should be applied to.]. Selection is discussed in detail in Section 4: Selection of ITS information.

4.1 Locations of Data Categories and Selection Mechanisms

Selections of ITS Information can appear in three places:

• in a schema: ITS data categories are expressed as schema annotation, and the selection is the element or attribute declaration which is being annotated

• global rules: the selection is realized as a selector attribute, which appears together with a data category attribute. The selector attribute contains an AbsoluteLocationPath as described in [XPath 1.0]

• in an instance document: the selection is realized using a data category attribute, which is attached to the selected element node. There is no additional selector attribute. The default selection for each data category defines whether the selection covers attributes and child elements. See Section 5.1: Position and Default Selections of Data Categories.

The various selection mechanisms are defined in detail below.

<xs:element name="p">
 <xs:annotation>
  <xs:appinfo>
   <its:schemaRule its:translate="yes"/>
  </xs:appinfo>
 </xs:annotation> ...
</xs:element>

<xs:attribute name="alt">
 <xs:annotation>
  <xs:appinfo>
   <its:schemaRule its:translate="yes"/>
  </xs:appinfo>
 </xs:annotation> ...
</xs:attribute>

<element name="p">
 <its:schemaRule its:translate="yes"/> ...
</element>

<attribute name="p">
 <its:schemaRule its:translate="yes"/> ...
</attribute>

<its:schemaRule its:translate="yes" its:locInfo="This has to be handled carefully"
its:locInfoType="alert"/>

<documentRules xmlns="http://www.w3.org/2005/11/its">
 <its:ns its:prefix="tei" its:uri="http://www.tei-c.org/ns/1.0"/>
 <documentRule its:translate="no" its:translateSelector="//tei:term"/>
 <documentRule its:translate="no" its:translateSelector="//qterm"/>
</its:documentRules>

<xs:schema>
 <xs:annotation>
  <xs:appinfo>
   <its:documentRules>
    <its:documentRule its:translate="no" its:translateSelector="//p[@editor='john']"/>
<!-- This rule holds for p elements which are edited by John. -->
   </its:documentRules>
  </xs:appinfo>
 </xs:annotation>
 <xs:element name="p">
  <xs:annotation>
   <xs:appinfo>
    <its:schemaRule its:translate="yes"/>
<!-- This rule holds for all p elements -->
    </xs:appinfo>
   </xs:annotation> ...
  </xs:element> ...
 </xs:schema>

<text>
 <head its:translate="no"> ... </head>
 <body its:translate="yes" its:dir="ltr"> ... </body>
</text>

4.2 Precedence between Selections

The following precedence order is defined for selections of ITS information in various positions (the first item in the list has the highest precedence):

1. Implicit selection in instance documents (data category attributes on a specific element)

2. Selections in instance documents (using a documentRules element)

3. Selections in an external file (using a documentRules element)

4. In a schema, selections expressed with a documentRules element

5. Selections expressed with schemaRule (See also the note in Section 4.1.2: Rule-based Selection)

6. Selections via defaults for data categories, see Section 5.1: Position and Default Selections of Data Categories

In case of conflicts between selections via multiple documentRule elements, the last selector has higher precedence.

<text>
 <head>
 <its:documentRules>
  <its:documentRule its:translate="yes" its:translateSelector="//p"/>
  <its:documentRule its:translate="no" its:translateSelector="//index/entry/p"/>
 <its:documentRules>
 </head>
 <body> ...
  <p its:translate="no"> ... </p>
 </body>
 <back><index>
  <entry><p> ... </p></entry>
 </index></back>
</text>

4.3 Mapping of ITS Data Categories to Existing Markup

Some markup schemes provide markup which can be used to express ITS data categories. ITS data categories can be mapped to such existing markup, using the selection mechanism described in Section 4.1.2: Rule-based Selection. In this way, there is no need to integrate ITS markup into documents.

<topic 
    xmlns="http://dita.oasis-open.org/architecture/2005/" 
    xmlns:its="http://www.w3.org/2005/11/its" 
    DITAArchVersion="1.0" id="myTopic">
  <title>The ITS Topic</title>
    <its:documentRules>
      <its:ns prefix="dita"
        uri="http://dita.oasis-open.org/architecture/2005/"/>
      <its:documentRule its:translateSelector="//*[@dita:translate='yes']" 
        its:translate="yes"/>
      <its:documentRule its:translateSelector="//*[@dita:translate='no']" 
        its:translate="no"/>
      <its:documentRule its:termSelector="//dita:term" its:term="yes"/>
      <its:documentRule its:termSelector="//dita:dt" its:term="yes"/>
    </its:documentRules>
  <body>[...] 
  <dlentry id="tDataCat">
    <dt>Data category</dt>
    <dd>ITS defines <term>data
    category</term> as an abstract concept for a particular type
    of information for internationalization and localization of XML
    schemas and documents.
    </dd>
    </dlentry>[...]  
    <p>For the implementation of ITS, apply the rules in the order:</p>
    <ul>
      <li>Default</li>
      <li>Rules in the schema</li>
      <li>Rules in the instance document</li>
      <li>Local attributes </li>
    </ul>
    <p>
      <ph translate="no" xml:lang="fr">Et voilà !</ph> The last rule wins
    </p>
  </body>
</topic>

5.1 Position and Default Selections of Data Categories

The following table summarizes the relations between data categories, location of their selection mechanisms, and default selections in instance documents.

5.2 Translatability

<xs:element name="p">
 <xs:annotation>
  <xs:appinfo>
   <its:schemaRule its:translate="yes"/>
  </xs:appinfo>
 </xs:annotation> ...
</xs:element>

<its:documentRules>
 <its:documentRule its:translate="yes" its:translateSelector="//p"/>
<!-- All p elements should be translated-->
</its:documentRules>

<book>
 <head>...</head> <body its:translate="yes"> ...  
  <p>And he said: you need a new 
  <quote its:translate="no">motherboard</quote> 
 </p> ...  </body>
</book>

5.3 Localization Information

<xs:element name="p">
 <xs:annotation>
  <xs:appinfo>
   <its:schemaRule
its:locInfo="This has to be handled carefully" its:locInfoType="alert"/>
  </xs:appinfo>
 </xs:annotation> ...
</xs:element>

<its:documentRules>
 <its:documentRule its:locInfo="This p element has to be handled carefully"
its:locInfoType="alert" its:locInfoSelector="/body/p[1]"/>
</its:documentRules>

<book>
 <head>...</head>
 <body> ...
  <p its:locInfo="This p element has to be handled
   carefully" its:locInfoType="alert">And he said: you need a new
   <quote>motherboard</quote>
  </p> ...
 </body>
</book>

5.4 Terminology

<xs:element name="span">
 <xs:annotation>
  <xs:appinfo>
   <its:schemaRule its:term="yes"/>
<!-- All span elements are used to mark up terms-->
  </xs:appinfo>
 </xs:annotation> ...
</xs:element>

<its:documentRules>
 <its:documentRule its:term="yes" its:termSelector="/body/p[1]/span"
its:termRef="http://example.com/termdatabase/#x142539"/>
</its:documentRules>

<book>
 <head>...</head> <body> ...  <p>And he said: you need a
 new <quote its:term="yes">motherboard</quote></p> ...
 </body> 
</book>

5.5 Directionality

<its:documentRules>
 <its:documentRule its:dir="rtl" its:dirSelector="/body/p[1]/quote[xml:lang='he']"/>
<!-- Some Hebrew quotation -->
</its:documentRules>

<book>
 <head>...</head> 
 <body> ...  <p>And he said: <quote
 its:dir="rtl"> ... a Hebrew quotation ... </quote></p>
 ...  </body> 
</book>

5.6 Ruby

<text>
 <head> ... </head>
 <body>
  <p>This is about the
    <its:ruby>
     <its:rubyBase>W3C</its:rubyBase>
     <its:rubyText>World Wide Web Consortium</its:rubyText>
    </its:ruby>.
  </p>
 </body>
</text>

<text ...>
 <head> ... </head>
  <its:documentRules>
   <its:documentRule its:rubyText="World Wide Web Consortium"
    its:rubySelector="/body/img[1]/@alt"/>
  </its:documentRules>
 <body>
  <img src="w3c_home.png" alt="W3C"/> ...
 </body>
</text>

6.1 ITS and XHTML 1.0

6.2 ITS and DocBook

TODO

6.3 ITS and Open Document Format 1.0

TODO

6.4 ITS and DITA 1.0

TODO

6.5 ITS and TEI

The TEI ([TEI]) is intended for literary and linguistic material, and is most often used for digital editions of existing printed material. It is also suitable, however, for general purpose writing. The P5 release of the TEI consists of 23 modules which can be combined together as needed.

<schemaSpec ident="tei-its" start="TEI">
 <moduleRef key="header"/>
 <moduleRef key="core"/>
 <moduleRef key="tei"/>
 <moduleRef key="textstructure"/>
 <moduleRef key="namesdates"/>
 <moduleRef key="msdescription"/> ...

<moduleRef url="its.rng">
 <content>
 <rng:define name="model.headerPart" combine="choice">
  <rng:ref name="documentRules"/>
 </rng:define>
 </content>
</moduleRef>

<classSpec ident="att.global" type="atts" mode="change">
  <attList>
   <attRef name="att.selector.attributes"/>
   <attRef name="att.datacats.attributes"/>
  </attList>
 </classSpec>
... </schemaSpec>

<TEI
 xmlns:its="http://www.w3.org/2005/11/its"
 xmlns="http://www.tei-c.org/ns/1.0">
 <teiHeader>
  <fileDesc>
<!-- details of the file -->
  </fileDesc>
  <documentRules xmlns="http://www.w3.org/2005/11/its">
   <ns its:prefix="t" its:uri="http://www.tei-c.org/ns/1.0"/>
   <documentRule its:translate="no"
     its:translateSelector="//t:body/t:p/@*"/>
   <documentRule its:translate="yes"
     its:translateSelector="//t:body/t:p"/>
  </documentRules>
 </teiHeader>
 <text>
  <body>
   <p rend="normal">Hello  <hi>world</hi></p>
   <p rend="special">Goodbye</p>
   <p its:translate="no">This must not be translated</p>
  </body>
 </text>
</TEI>

6.6 ITS and XML Spec

[XMLSPEC] is intended for W3C working drafts, notes, recommendations, and all other document types that fall under the category of technical reports. XML Spec is available in the formats of XML DTD, XML Schema and RELAX NG.

<its:documentRules xmlns:its="http://www.w3.org/2005/11/its">
 <!--The following rules are for xmlspec-i18n.dtd-->
 <its:documentRule its:term="yes" its:termSelector="//qterm"/>
 <its:documentRule its:dir="ltr" its:dirSelector="//*[@dir='ltr']"/>
 <its:documentRule its:dir="rtl" its:dirSelector="//*[@dir='rtl']"/>
 <its:documentRule its:dir="lro" its:dirSelector="//*[@dir='lro']"/>
 <its:documentRule its:dir="rlo" its:dirSelector="//*[@dir='rlo']"/>
 <its:documentRule its:locInfo="" its:locInfoType="alert"
   its:locInfoSelector="//@locn-alert"/>
 <its:documentRule its:locInfo="" its:locInfoType="description"
   its:locInfoSelector="//@locn-note"/>
 <its:documentRule its:translate="yes" 
   its:translateSelector="//*[@translate='yes']"/>
 <its:documentRule its:translate="no" 
   its:translateSelector="//*[@translate='no']"/>
 <!--This rule is for the original XML Spec DTD-->
 <its:documentRule its:term="yes" its:termSelector="//term"/>
</its:documentRules>

7.1 Declaration of the Span Element

<text>
 <head>[...]</head>
 <body> ...
  <its:span its:translate="no"> ... </its:span>
 </body>
</text>

7.2 Declarations of General Datatypes

A data type data.selector is defined for selector attributes. Its value is an XPath expression [XPath 1.0]. A data type itsBoolean is defined for boolean values, e.g. to express translatability. The data type dirValues is used for the data category attribute dir . The data type locInfoType is used to express the type of the locInfo attribute. The data type itsBooleanTrue is used for the term attribute.

data.selector

[4]

data.selector

::=

text

data.itsBoolean

[5]

data.itsBoolean

::=

"yes" | "no"

data.dirValues

[6]

data.dirValues

::=

"ltr" | "rtl" | "lro" | "rlo"

data.locInfoType

[7]

data.locInfoType

::=

"alert" | "description"

data.itsBooleanTrue

[8]

data.itsBooleanTrue

::=

"yes"

7.3 Declarations of Data Categories

The attribute group att.datacats is used to express the ITS data categories. It makes use of the data type data.itsBoolean.

att.datacats

[9]	att.datacats.attributes	::=	att.datacats.attribute.translate, att.datacats.attribute.locInfo, att.datacats.attribute.locInfoType, att.datacats.attribute.term, att.datacats.attribute.termRef, att.datacats.attribute.dir, att.datacats.attribute.rubyText, empty
[10]	att.datacats.attribute.translate	::=	attribute translate { data.itsBoolean }?
[11]	att.datacats.attribute.locInfo	::=	attribute locInfo { text }?
[12]	att.datacats.attribute.locInfoType	::=	attribute locInfoType { data.locInfoType }?
[13]	att.datacats.attribute.term	::=	attribute term { data.itsBooleanTrue }?
[14]	att.datacats.attribute.termRef	::=	attribute termRef { xsd:anyURI }?
[15]	att.datacats.attribute.dir	::=	attribute dir { data.dirValues }?
[16]	att.datacats.attribute.rubyText	::=	attribute rubyText { text }?

The elements ruby , rubyBase and rubyText are used for the implementation of the Ruby data category. If change the element markup in an XML document is not possible, the rubyText and rubySelector attributes should be used.

rubyBase

[17]	rubyBase	::=	element :rubyBase { rubyBase.content }
[18]	rubyBase.content	::=	text

ruby

[19]	ruby	::=	element :ruby { ruby.content }
[20]	ruby.content	::=	rubyBase, rubyText

rubyText

[21]	rubyText	::=	element :rubyText { rubyText.content }
[22]	rubyText.content	::=	text

7.4 Declaration of Selector Attributes

The attribute group att.selector is used at the documentRule element to express applicability of ITS information. It must not be used in other positions, e.g. individual elements. It makes use of the data type data.selector.

att.selector

[23]	att.selector.attributes	::=	att.selector.attribute.translateSelector, att.selector.attribute.locInfoSelector, att.selector.attribute.termSelector, att.selector.attribute.dirSelector, att.selector.attribute.rubySelector, empty
[24]	att.selector.attribute.translateSelector	::=	attribute translateSelector { data.selector }?
[25]	att.selector.attribute.locInfoSelector	::=	attribute locInfoSelector { data.selector }?
[26]	att.selector.attribute.termSelector	::=	attribute termSelector { data.selector }?
[27]	att.selector.attribute.dirSelector	::=	attribute dirSelector { data.selector }?
[28]	att.selector.attribute.rubySelector	::=	attribute rubySelector { data.selector }?

7.5 Declarations of the SchemaRule and DocumentRules Elements

The schemaRule element contains rules for ITS information, to be used as schema annotation. It uses attributes from the ITS data categories.

schemaRule

[29]	schemaRule	::=	element :schemaRule { schemaRule.content, schemaRule.attributes }
[30]	schemaRule.content	::=	empty
[31]	schemaRule.attributes	::=	att.datacats.attributes, empty

The documentRules element contains zero or more ns elements, followed by one or more documentRule elements. The documentRule element contains attributes from the data category attributes, and the selector attributes.

documentRules

[32]	documentRules	::=	element :documentRules { documentRules.content, documentRules.attributes }
[33]	documentRules.content	::=	ns*, documentRule+
[34]	documentRules.attributes	::=	empty

ns

[35]	ns	::=	element :ns { ns.content, ns.attributes }
[36]	ns.content	::=	empty
[37]	ns.attributes	::=	att.nsident.attributes, empty

att.nsident

[38]	att.nsident.attributes	::=	att.nsident.attribute.prefix, att.nsident.attribute.uri, empty
[39]	att.nsident.attribute.prefix	::=	attribute prefix { xsd:NCName }
[40]	att.nsident.attribute.uri	::=	attribute uri { xsd:anyURI }

documentRule

[41]	documentRule	::=	element :documentRule { documentRule.content, documentRule.attributes }
[42]	documentRule.content	::=	empty
[43]	documentRule.attributes	::=	att.selector.attributes, att.datacats.attributes, empty

8.1 Conformance to the ITS Data Categories and Data Category Specific Default Selection Mechanisms

An implementation of the ITS data categories is conformant if it supplies a schema which adopts the ITS data categories, with the following constraints:

• The schema must allow the usage of the attribute group att.datacats at every element which is declared in the schema.

• The interpretation of data category attributes in instance documents must be conformant to the data category specific default selections described in Section 5.1: Position and Default Selections of Data Categories.

• The schema should allow the usage of the documentRules element at one or more elements in the schema.

The schemaRule element is to be used as schema annotations. It is the responsibility of the schema processor to allow for such annotations.

<xs:schema xmlns:myns="http://example.com/mySchema"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:its="http://www.w3.org/2005/11/its"
targetNamespace="http://example.com/mySchema" elementFormDefault="qualified"
attributeFormDefault="unqualified">
 <xs:import namespace="http://www.w3.org/2005/11/its" schemaLocation="its.xsd"/>
 <xs:element name="document">
  <xs:complexType>
   <xs:sequence>
     <xs:element ref="myns:head"/>
     <xs:element ref="myns:body"/>
   </xs:sequence>
   <xs:attributeGroup ref="myns:commonAtts"/>
  </xs:complexType>
 </xs:element>
 <xs:attributeGroup name="commonAtts">
  <xs:attributeGroup ref="its:att.datacats.attributes"/>
  <xs:attributeGroup ref="its:att.selector.attributes"/>
 </xs:attributeGroup>
 <xs:element name="head">
  <xs:complexType>
   <xs:choice minOccurs="0" maxOccurs="unbounded">
     <xs:element ref="its:documentRules"/>
     <xs:element ref="its:documentRule"/>
   </xs:choice>
   <xs:attributeGroup ref="myns:commonAtts"/>
  </xs:complexType>
 </xs:element>
 <xs:element name="body">
  <xs:complexType>
   <xs:sequence>
    <xs:element ref="myns:para" maxOccurs="unbounded"/>
   </xs:sequence>
   <xs:attributeGroup ref="myns:commonAtts"/>
  </xs:complexType>
 </xs:element>
 <xs:element name="para">
  <xs:complexType mixed="true">
   <xs:attributeGroup ref="myns:commonAtts"/>
  </xs:complexType>
 </xs:element>
</xs:schema>

8.2 Conformance to Selection Mechanisms

Conformance to Selection Mechanisms encompasses conformance to the ITS data categories and data category specific default selection mechanisms, with the following changes:

• The schema must allow the usage of the documentRules element in at least one element in the schema

• An application which processes ITS elements and attributes must process the selection mechanisms described in Section 4.2: Precedence between Selections

A mandatory part of this conformance criterion is the usage of XPath. An application which processes ITS selection rules must be able to process XPath in version 1.0 or higher. It is not required to support a specific host language of XPath, like for example [XSLT 1.0].