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Please refer to the errata for this document, which may include some normative corrections.
See also translations.
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Copyright © 2007 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
This document defines data categories and their implementation as a set of elements and attributes called the Internationalization Tag Set (ITS). ITS is designed to be used with schemas to support the internationalization and localization of schemas and documents. An implementation is provided for three schema languages: XML DTD, XML Schema and RELAX NG.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This document defines data categories and their implementation as a set of elements and attributes called the Internationalization Tag Set (ITS). ITS is designed to be used with schemas to support the internationalization and localization of schemas and documents. An implementation is provided for three schema languages: XML DTD, XML Schema and RELAX NG.
This is a Recommendation of the W3C. It has been developed by the W3C Internationalization Tag Set (ITS) Working Group, which is part of the Internationalization Activity.
This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web.
Please make comments about this document using W3C's public Bugzilla system. We recommend using Bugzilla for making comments (instructions can be found at How to use the Issues Tracking System for the ITS Tagset Working Draft). If this is not feasible, comments may also be sent to www-i18n-comments@w3.org. Use "[Comment on ITS WD]" in the subject line of your email. A list of ITS tagset related comments and issues in Bugzilla and the www- i18n-comments archives are publicly available.
This document incorporates minor changes made against the Proposed Recommendation of 21 November 2006; please see the Revision Log for details. The implementation report and test suite provide further implementation information.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
This section is informative.
ITS is a technology to easily create XML which is internationalized and can be localized effectively. On the one hand, the ITS specification identifies concepts (such as "directionality") which are important for internationalization and localization. On the other hand, the ITS specification defines implementations of these concepts (termed "ITS data categories") as a set of elements and attributes called the Internationalization Tag Set (ITS). The document provides implementations for three schema languages: XML DTD [XML 1.0], XML Schema [XML Schema] and RELAX NG [RELAX NG].
This document aims to realize many of the ideas formulated in [Localizable DTDs].
Requirements for this document are formulated in [ITS REQ]. Not all requirements listed there are addressed in this document. Those which are not addressed here are either covered in [XML i18n BP] or may be addressed in a future version of this specification.
This document covers the following requirements:
R006 - identifying language/locale, see Section 6.7: Language Information
R008 - purpose specification/mapping, see Section 5.5: Associating ITS Data Categories with Existing Markup
R011 - bidirectional text support, see Section 6.5: Directionality
R012 - indicator of translatability, see Section 6.2: Translate
R014 - limited impact, see Section 5.5: Associating ITS Data Categories with Existing Markup
R017 - localization notes, see Section 6.3: Localization Note
R025 - elements and segmentation, see Section 6.8: Elements Within Text
The following requirements will be addressed in [XML i18n BP]:
The Working Group decided not to cover the following requirements at this time to be able to focus on the most important ones.
Content or software that is authored in one language (so-called source language) is often made available in additional languages or adapted with regard to other cultural aspects. This is done through a process called localization, where the original material is translated and adapted to the target audience.
In addition, document formats expressed by schemas may be used by people in different parts of the world, and these people may need special markup to support the local language or script. For example, people authoring in languages such as Arabic, Hebrew, Persian or Urdu need special markup to specify directionality in mixed direction text.
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 and DITA as formats 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 document need to be translated. Tools often cannot automatically do this identification.
In this document it is difficult to make distinction between the string elements that are translatable and the ones that are not. Only the addition of flags could resolve the issue.
<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>
[Source file: EX-motivation-its-1.xml]
Even when metadata are available to identify non-translatable text, the conditions may be quite complex and not directly indicated
with a simple flag. Here, for instance, only the text in the nodes matching the expression //component[@type!='image']/data[@type='text'] is translatable.
<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> <component id="792" type="string"> <data type="text">Number of files: </data> </component> </rsrc> </dialogue>
[Source file: EX-motivation-its-2.xml]
The ITS specification aims to provide different types of users with information about what markup should be supported to enable worldwide use and effective internationalization and localization of content. The following paragraphs sketch these different types of users, and their usage of ITS.
Schema developers who start a schema from ground up
This type of user will find proposals for attribute and element names to be included in their new schema (also called "host vocabulary"). Using the attribute and element names proposed in the ITS specification may be helpful because it leads to easier recognition of the concepts represented by both schema users and processors. It is perfectly possible, however, for a schema developer to develop his own set of attribute and element names. The specification sets out, first and foremost, to ensure that the required markup is available, and that the behavior of that markup meets established needs.
Schema developers who work with an existing schema
This type of user will be working with schemas such as DocBook, DITA, or perhaps a proprietary schema. The ITS Working Group has sought input from experts developing widely used formats such as the ones mentioned.
Note:
The question "How to use ITS with existing popular markup schemes?" is covered in more details (including examples) in a separate document: [XML i18n BP].
Developers working on existing schemas should check whether their schemas support the markup proposed in this specification, and, where appropriate, add the markup proposed here to their schema.
In some cases, an existing schema may already contain markup equivalent to that recommended in ITS. In this case it is not necessary to add duplicate markup since ITS provides mechanisms for associating ITS markup with markup in the host vocabulary which serves a similar purpose (see Section 5.5: Associating ITS Data Categories with Existing Markup). The developer should, however, check that the behavior associated with the markup in their own schema is fully compatible with the expectations described in this specification.
Vendors of content-related tools
This type of user includes companies which provide tools for authoring, translation or other flavors of content-related software solutions. It is important to ensure that such tools enable worldwide use and effective localization of content. For example, translation tools should prevent content marked up as not for translation from being changed or translated. It is hoped that the ITS specification will make the job of vendors easier by standardizing the format and processing expectations of certain relevant markup items, and allowing them to more effectively identify how content should be handled.
Content producers
This type of user comprises authors, translators and other types of content author. The markup proposed in this specification may be used by them to mark up specific bits of content. Aside: The burden of inserting markup can be removed from content producers by relating the ITS information to relevant bits of content in a global manner (see global, rule-based approach). This global work, however, may fall to information architects, rather than the content producers themselves.
In order to support all of these users, the information about what markup should be supported to enable worldwide use and effective localization of content is provided in this specification in two ways:
abstractly in the data category descriptions: Section 6: Description of Data Categories
concretely in the ITS schemas: Appendix D: Schemas for ITS
The ITS specification proposes several mechanisms for supporting worldwide use and effective internationalization and localization of content. We will sketch them below by looking at them from the perspectives of certain user types. For the purpose of illustration, we will demonstrate how ITS can indicate that certain parts of content should or should not be translated.
A content author uses an attribute on a particular element to say that the text in the element should not be translated.
The its:translate="no" attributes indicate that the path and the cmd elements should not be translated.
<help xmlns:its="http://www.w3.org/2005/11/its" its:version="1.0"> <head> <title>Building the Zebulon Toolkit</title> </head> <body> <p>To re-compile all the modules of the Zebulon toolkit you need to go in the <path its:translate="no">\Zebulon\Current Source\binary</path> directory. Then from there, run batch file <cmd its:translate="no">Build.bat</cmd>.</p> </body> </help>
[Source file: EX-ways-to-use-its-1.xml]
A content author or information architect uses markup at the top of the document to identify a particular type of element or context in which the content should not be translated.
The translateRule element is used in the header of the document to indicate that none of the path or cmd elements should be translated.
<help xmlns:its="http://www.w3.org/2005/11/its" its:version="1.0"> <head> <title>Building the Zebulon Toolkit</title> <its:rules version="1.0"> <its:translateRule selector="//path | //cmd" translate="no"/> </its:rules> </head> <body> <p>To re-compile all the modules of the Zebulon toolkit you need to go in the <path>\Zebulon\Current Source\binary</path> directory. Then from there, run batch file <cmd>Build.bat</cmd>.</p> </body> </help>
[Source file: EX-ways-to-use-its-2.xml]
A processor may insert markup at the top of the document which links to ITS information outside of the document.
A rules element is inserted in the header of the document. It has a XLink href attribute used to link to an ITS external rule document.
<help xmlns:its="http://www.w3.org/2005/11/its" xmlns:xlink="http://www.w3.org/1999/xlink" its:version="1.0"> <head> <title>Building the Zebulon Toolkit</title> <its:rules version="1.0" xlink:href="EX-ways-to-use-its-4.xml" xlink:type="simple"/> </head> <body> <p>To re-compile all the modules of the Zebulon toolkit you need to go in the <path>\Zebulon\Current Source\binary</path> directory. Then from there, run batch file <cmd>Build.bat</cmd>.</p> </body> </help>
[Source file: EX-ways-to-use-its-3.xml]
The rules element contains several ITS rules that are common to different documents. One of them is a translateRule element that indicates that no path or cmd element should be translated.
<its:rules xmlns:its="http://www.w3.org/2005/11/its" version="1.0"> <its:translateRule selector="//path | //cmd" translate="no"/> </its:rules>
[Source file: EX-ways-to-use-its-4.xml]
A schema developer integrates ITS markup declarations in his schema to allow users to indicate that specific parts of the content should not be translated.
The declarations for the translate attribute is added to a group of common attributes commonAtts. This allows to use the translate attribute within the documents like in Example 3.
<xs:schema xmlns:its="http://www.w3.org/2005/11/its" xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"> <xs:import namespace="http://www.w3.org/2005/11/its" schemaLocation="its.xsd"/> <xs:attributeGroup name="commonAtts"> <xs:attributeGroup ref="its:att.local.with-ns.attribute.translate"/> <xs:attribute name="id" type="xs:ID" use="optional"/> </xs:attributeGroup> <xs:element name="help"> <xs:complexType> <xs:sequence> <xs:element name="head"> <xs:complexType> <xs:sequence> <xs:element name="title" type="xs:string"/> </xs:sequence> <xs:attributeGroup ref="commonAtts"/> </xs:complexType> </xs:element> <xs:element name="body"> <xs:complexType> <xs:choice minOccurs="1" maxOccurs="unbounded"> <xs:element name="p"> <xs:complexType mixed="true"> <xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:element ref="path"/> <xs:element ref="cmd"/> </xs:choice> <xs:attributeGroup ref="commonAtts"/> </xs:complexType> </xs:element> </xs:choice> </xs:complexType> </xs:element> </xs:sequence> <xs:attributeGroup ref="its:att.version.attribute.version"/> </xs:complexType> </xs:element> <xs:element name="path"> <xs:complexType mixed="true"> <xs:attributeGroup ref="commonAtts"/> </xs:complexType> </xs:element> <xs:element name="cmd"> <xs:complexType mixed="true"> <xs:attributeGroup ref="commonAtts"/> </xs:complexType> </xs:element> </xs:schema>
[Source file: EX-ways-to-use-its-5.xsd]
The first two approaches above can be likened to the
use of CSS in [XHTML 1.0]. Using a style attribute,
an XHTML content author may assign a color to a
particular paragraph. That author could also have used the
style element at the top of the page to say that
all paragraphs of a particular class or in a particular
context would be colored red.
This standard does not cover all mechanisms and data formats (sometimes called Localization Properties), which might be needed for configuring localization workflows or tools to process a specific format. However, these mechanisms and data formats may be implemented using the framework described in this standard.
Note:
"XML localization properties" is a generic term to name the mechanisms and data formats that allow localization tools to be configured in order to process a specific XML format. Examples of "XML localization properties" are the Trados "DTD Settings" file, and the SDLX "Analysis" file.
Abstraction via data categories: ITS defines data categories as an abstract notion for information for internationalization and localization of XML schemas and documents. This abstraction is helpful in realizing independence from a particular implementation using for example an element or attribute. See Section 3.3: Data category for a definition of the term data categories, Section 6: Description of Data Categories for the definition of the various ITS data categories, and subsections in Section 6: Description of Data Categories for the data category implementations.
Powerful selection mechanism: For ITS markup which appears in an XML instance, it has to be clearly defined to which XML nodes the ITS-related information pertains. Thus, ITS defines selection mechanisms to specify to what parts of an XML document an ITS data category and its values should be applied. Selection relies on the information which is given in the XML Information Set [XML Infoset]. ITS applications may implement inclusion mechanisms such as XInclude or DITA's [DITA 1.0] conref.
Content authors need, for example, a simple way to work
with the Translate data category in order to express whether the content of an
element or attribute should be translated or
not. Localization coordinators, on the other hand, need an
efficient way of managing translations of large document
sets based on the same schema. This could by realized by a
specification of defaults for the Translate data category and exceptions
from the defaults (e.g. all p elements should be
translated, but not p elements inside of an
index element).
To meet these requirements this specification introduces mechanisms that add ITS information to XML documents, see Section 5: Processing of ITS information. These mechanisms also provide a means for specifying ITS information for attributes (a task for which no standard means yet exists).
The ITS selection mechanisms allows you to provide information about content locally (specified at the XML node to which it pertains) or globally (specified in another part of the document). Global selection mechanisms can be in the same document, or in a separate file.
No dedicated 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 dedicated 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 1.0], 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 6.6: Ruby.
ITS has no dependency on technologies which are still under development
ITS fits with existing work in the W3C architecture (e.g. use of [XPath 1.0] for the selection mechanism)
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:
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.
The content models for elements and attributes are written using embedded RELAX NG XML notation.
Documentation for elements, attributes, value lists etc. is written inline, along with examples and other supporting material.
XSLT transformations are provided by the TEI to create documentation into 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.
This section is informative.
Information (e.g. "translate this") captured by ITS markup
(e.g. its:translate='yes') always pertains to
one or more XML nodes (mainly element and attribute nodes). In
a sense, ITS markup "selects" the XML node(s). Selection may
be explicit or implicit. ITS distinguishes two approaches to
selection: local, and with global rules.
The mechanisms defined for ITS selection resemble those
defined in [CSS 2.1]. The local
approach can be compared to the style attribute in
HTML/XHTML, and the approach with global rules is similar to the
style element in HTML/XHTML. In contrast to CSS, ITS uses
XPath for identifying nodes. Thus,
the local approach puts ITS markup in the relevant
element of the host vocabulary (e.g. the author
element in DocBook)
the rule-based, global approach puts the ITS markup in elements defined by ITS itself (namely the rules element)
ITS markup can be used with XML documents (e.g. a DocBook article), or schemas (e.g. an XML Schema document for a proprietary document format). Since each usage defines some specific requirements, ITS markup may take different shapes.
The following two examples sketch the distinction between the local and global approaches.
The document in Example 8 shows how a content author may use the
ITS translate attribute to indicate
that all content inside the author element should be protected from
translation. Translation tools that are aware of the meaning
of this attribute can then screen the relevant content from
the translation process.
<dbk:article xmlns:its="http://www.w3.org/2005/11/its" xmlns:dbk="http://docbook.org/ns/docbook" its:version="1.0" version="5.0" xml:lang="en"> <dbk:info> <dbk:title>An example article</dbk:title> <dbk:author its:translate="no"> <dbk:personname> <dbk:firstname>John</dbk:firstname> <dbk:surname>Doe</dbk:surname> </dbk:personname> <dbk:affiliation> <dbk:address> <dbk:email>foo@example.com</dbk:email> </dbk:address> </dbk:affiliation> </dbk:author> </dbk:info> <dbk:para>This is a short article.</dbk:para> </dbk:article>
[Source file: EX-basic-concepts-1.xml]
For this to work, the schema developer will need to add the translate attribute to the schema as a common attribute or on all the relevant element definitions. Note how there is an expectation in this case that inheritance plays a part in identifying which content does have to be translated and which does not. Tools that process this content for translation will need to implement the expected inheritance.
The document in Example 9 shows a different approach to identifying
non-translatable content, similar to that used with a
style element in [XHTML 1.0], but using an ITS-defined
element called rules. It works as follows: A document
can contain a rules element (placed where it does not impact the
structure of the document, like in a "head" section). It contains one or more
ITS rule elements (for example
translateRule). Each of these specific elements
contains a selector attribute. As its name
suggests, this attribute selects the XML node
or nodes to which a corresponding ITS information
pertains. The values of ITS selector attributes are XPath
absolute location paths. Information for the handling of
namespaces in these path expressions is taken from namespace
declarations [XML Names] at the current rules element.
Note:
Caveat Related to XSLT-based Processing of ITS Selector Attributes
The values of ITS selector attributes are XPath absolute location paths. Accordingly, the following is a legitimate value:
myElement/descendant-or-self::*/@*
Unfortunately, values like this cause trouble when they are used in
XSLT-based processing of ITS where the values of the ITS selector attributes are used as values
of match attributes of XSLT templates. The reason for this is the following: match attributes
may only contain a restriction/subset of XPath expressions, so-called
patterns.
Basically the following restrictions hold for patterns:
only axes "child" or "attribute" allowed
"//" or "/" possible
id() or key() function possible
predicates possible
Using only XSLT patterns in ITS selector attributes helps to avoid this issue. In many cases, this is possible by using patterns with predicates. The value above may for example be rewritten as follows:
*[self::myElement]/@* | myElement//*/@*
<myTopic xmlns:its="http://www.w3.org/2005/11/its" xmlns="myNamescapeURI" id="topic01" xml:lang="en-us"> <prolog> <title>Using ITS</title> <its:rules version="1.0"> <its:translateRule selector="//n:term" translate="no"/> </its:rules> </prolog> <body> <p>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.</p> </body> </myTopic>
[Source file: EX-basic-concepts-2.xml]
For this approach to work, the schema developer needs to add the rules element and associated markup to the schema.
In some cases this may allow the schema developer to avoid adding other ITS markup (such as an translate attribute) to the elements in the schema. However, it is likely that authors will want to use attributes on markup from time to time to override the general rule.
For specification of the Translate data category information, the contents of the rules element would normally be designed by an information architect familiar with the document format and familiar with, or working with someone familiar with, the needs of the localization group.
The global, rule-based approach has the following benefits:
Content authors do not have to concern themselves with
creating additional markup or verifying that the markup was
applied correctly. ITS data categories are associated with
sets of XML nodes (for example all p elements in an
XML instance)
Changes can be done in a single location, rather than by searching and modifying the markup throughout a document (or documents, if the rules element is stored as an external entity)
ITS data categories can designate attribute values as well as elements.
It is possible to associate ITS markup with existing
markup (for example the term element in DITA)
The commonality in both examples above is the markup
translate='no'. This piece of ITS markup can
be interpreted as follows:
The ITS selector attribute allows:
ITS data category attributes to appear in global rules (even outside of an XML document or schema)
ITS data categories attributes to pertain to sets of
XML nodes (for example all p elements in an XML
document)
ITS markup to pertain to attributes
ITS markup to
associate with existing markup (for example the term element in DITA)
The power of the ITS selection mechanisms comes at a price: rules related to overriding/precedence, and inheritance, have to be established.
The document in Example 10 shows how inheritance and overriding work for the
Translate data category. By default elements are translatable. Here, the translateRule element declared in the header overrides the default for the head element inside text and for all its children. Because the title element is actually translatable, the global rule needs to be overridden by a local its:translate="yes". Note that the global rule is processed first, regardless of its position inside the document. In the main body of the document,
the default applies, and here it is its:translate="no" that is used to set "faux pas" as non-translatable.
<text xmlns:its="http://www.w3.org/2005/11/its" > <head> <revision>Sep-10-2006 v5</revision> <author>Ealasaidh McIan</author> <contact>ealasaidh@hogw.ac.uk</contact> <title its:translate="yes">The Origins of Modern Novel</title> <its:rules version="1.0"> <its:translateRule translate="no" selector="/text/head"/> </its:rules> </head> <body> <div xml:id="intro"> <head>Introduction</head> <p>It would certainly be quite a <span its:translate="no">faux pas</span> to start a dissertation on the origin of modern novel without mentioning the <tl>Epic of Gilgamesh</tl>...</p> </div> </body> </text>
[Source file: EX-basic-concepts-3.xml]
For some data categories, special attributes add or point to information about the selected nodes. For example, the Localization Note data category can add information to selected nodes (using a locNote element), or point at existing information elsewhere in the document (using a locNotePointer attribute).
The functionality of adding information to the selected nodes is available for each data category except Language Information. Pointing to existing information is not possible for data categories that express a closed set of values; that is: Translate, Directionality and Elements Within Text.
The functionalities of adding information and pointing to existing information are mutually exclusive. That is to say, attributes for pointing and adding must not appear at the same rule element.
This section is normative.
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"
http://www.w3.org/1999/xlink for the XLink namespace, here used with the prefix "xlink"
[Definition: Schema language refers in this specification to an XML-related modeling or validation language such as XML DTD, XML Schema or RELAX NG.]
Note:
This specification provides schemas in the format of XML DTD, XML Schema or RELAX NG. However, these schemas are only non-normative; conformance for ITS markup declarations defines only mandatory positions of ITS declarations in schemas. This makes it possible to use ITS with any schema language that allows for using these positions.
[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 6: Description of Data Categories
schema language independent formalization, see the "markup declarations" subsections in Section 6: Description of Data Categories
schema language specific implementations, see Appendix D: Schemas for ITS
The Translate data category conveys information as to whether a piece of content should be translated or not.
The simplest formalization of this prose description on a schema language independent level is a translate attribute with two possible values: "yes" and "no". An implementation on a schema language specific level would be the declaration of the translate attribute in, for example, an XML DTD, an XML Schema document or an RELAX NG document. A different implementation would be a translateRule element that allows for specifying global rules about the Translate data category.
[Definition: selection encompasses mechanisms to specify to what parts of an XML document an ITS data category and its values should be applied to.] Selection is discussed in detail in Section 5: Processing of ITS information. Selection can be applied globally, see Section 5.2.1: Global, Rule-based Selection, and locally, see Section 5.2.2: Local Selection in an XML Document. As for global selection, ITS information can be added to the selected nodes, or it can point to existing information which is related to selected nodes.
Selection relies on the information that is given in the XML Information Set [XML Infoset]. ITS applications MAY implement inclusion mechanisms such as XInclude or DITA's [DITA 1.0] conref.
Note:
The selection of the ITS data categories applies to textual values contained within element or attribute nodes. In
some cases these nodes form pointers to other resources; a well-known
example is the src attribute on the img element in
HTML. The ITS Translate data category applies to the
text of the pointer itself, not the object to which it points. Thus in
the following example, the translation information specified via the translateRule element applies to the filename
"instructions.jpg", and is not an instruction to open the
graphic and change the words therein.
<text xmlns:its="http://www.w3.org/2005/11/its" > <its:rules version="1.0"> <its:translateRule translate="yes" selector="//p/img/@src"/> </its:rules> ... <p>As you can see in <img src="instructions.jpg"/>, the truth is not always out there.</p> </text>
[Source file: EX-notation-terminology-1.xml]
The attributes href, locNoteRef and termInfoRef which contain resource identifiers MUST allow the usage of Internationalized Resource Identifiers (IRIs, [RFC 3987] or its successor) to ease the adoption of ITS in international application scenarios.
Note:
The ITS schemas in Appendix D: Schemas for ITS are not normative. Hence this specification defines no validation requirements for IRI values in ITS markup. For processing of these values, relying on IRIs imposes no specific requirements. The reason is that the processing happens on the info set level [XML Infoset], where no difference between IRIs and URIs exists.
This section is normative.
The usage of the term conformance clause in this section is in compliance with [QAFRAMEWORK].
This specification defines two types of conformance: conformance of 1) ITS markup declarations , and conformance of 2) processing expectations for ITS Markup. These conformance types complement each other. An implementation of this specification MAY use them separately or together.
Description: ITS markup declarations encompass all declarations that are part of the Internationalization Tag Set. They do not concern the usage of the markup in XML documents. Such markup is subject to the conformance clauses in Section 4.2: Conformance Type 2: The Processing Expectations for ITS Markup.
Definitions related to this conformance type: ITS markup declarations are defined in various subsections in Section 5: Processing of ITS information and Section 6: Description of Data Categories (e.g. Section 6.3.3: Markup Declarations for Localization Note) in a schema language independent manner, relying on the ODD language. Their occurrence in other sections of this document is typographically marked via bold face and color.
Who uses this conformance type: Schema designers integrating ITS markup declarations into a schema. All conformance clauses for this conformance type concern the position of ITS markup declarations in that schema, and their status as mandatory or optional.
Conformance clauses:
1-1: At least one of the following MUST be in the schema:
rules element
one of the local ITS attributes
span element
ruby element
1-2: If the rules element is
used, it MUST be part of the
content model of at least one element declared in the
schema. It SHOULD be in a
content model for meta information, if this is available
in that schema (e.g. the head element in
[XHTML 1.0]).
1-3: If the ruby element is used, it SHOULD be declared as an inline element.
1-4: If the span element is used, it SHOULD be declared as an inline element.
Full implementations of this conformance type will implement all markup declarations for ITS. Statements related to this conformance type MUST list all markup declarations they implement.
Examples: Examples of the usage of ITS markup declarations in various existing schemas are given in a separate document [XML i18n BP].
Note:
Since the ITS markup declarations are schema language independent, each schema language can use its own, possibly multiple, mechanisms to implement the conformance clauses for ITS markup declarations. For example, an XML DTD can use parameter entities to encapsulate the ITS local attributes, or declare them directly for each element. The appropriate steps to integrate ITS into a schema depend on the design of this schema (e.g. whether it already has a customization layer that uses parameter entities). The ITS schemas in the format of XML DTD, XML Schema and RELAX NG in Appendix D: Schemas for ITS are only informative examples.
Description: Processors need to compute the ITS information that pertains to a node in an XML document. The ITS processing expectations define how the computation has to be carried out. Correct computation involves support for selection mechanism, defaults / inheritance / overriding characteristics, and precedence. The markup MAY be valid against a schema which conforms to the clauses in Section 4.1: Conformance Type 1: ITS Markup Declarations.
Definitions related to this conformance type: The processing expectations for ITS markup make use of selection mechanisms defined in Section 5: Processing of ITS information. The individual data categories defined in Section 6: Description of Data Categories have defaults / inheritance / overriding characteristics, and allow for using ITS markup in various positions (global and local).
Who uses this conformance type: Applications that need to process for internationalization or localization the nodes captured by a data category. Examples of this type of application are: ITS markup-aware editors, or translation tools that make use of ITS markup to filter translatable text as an input to the localization process.
Note:
Application-specific processing (that is processing that goes beyond the computation of ITS information for a node) such as automated filtering of translatable content based on the Translate data category is not covered by the conformance clauses below.
Note:
The ITS Working group provides a test suite to help implementers to write applications that support the ITS specifications. The test suite provides pairs of input and output files.
Conformance clauses:
2-1: A processor MUST implement at least one data category. For each implemented data category, the following MUST be taken into account:
2-1-1: processing of at least one selection mechanism (global or local).
2-1-2: the default selections for the data category.
2-1-3: the precedence definitions for selections defined in Section 5.4: Precedence between Selections, for the type of selections it processes.
2-2: If an application claims to process ITS markup for the global selection mechanism, it MUST process an XLink href attribute found on a rules elements.
Statements related to this conformance type MUST list all data categories they implement, and for each data category which type of selection they support.
This section is normative.
The version of the ITS schema defined in this specification is
"1.0". The version is indicated by the ITS
version attribute. This attribute is mandatory for the
rules element, where it MUST be in no namespace. If there is no rules element in an
XML document, a prefixed ITS version attribute
(e.g. its:version) MUST be provided at the
root element of the document. If there is both a version
attribute at the root element and a rules element in a
document, they MUST NOT specify
different versions.
Each XML document can have a different version. That is: if external rules are linked via an XLink href attribute on the rules element, they can specify a different version than the rules element.
ITS data categories can appear in two places:
Global rules: the selection is realized within a rules element. It contains rule elements for each data category. Each rule element has a selector attribute and possibly other attributes. The selector attribute contains an AbsoluteLocationPath as described in XPath 1.0 or its successor.
Locally in a document: the selection is realized using ITS local attributes, which are attached to an element node, or the span or ruby element. There is no additional selector attribute. The default selection for each data category defines whether the selection covers attributes and child elements. See Section 6.1: Position, Defaults, Inheritance and Overriding of Data Categories.
The two locations are described in detail below.
Global, rule-based selection is implemented using the rules element. It contains zero or more rule elements. Each rule element has a mandatory selector attribute. This attribute and all other possible attributes on rule elements are in the empty namespace and used without a prefix.
If there is more than one rules element in an XML document, the rules from each section are to be processed at the same precedence level. The rules sections are to be read in document order, and the ITS rules with them processed sequentially. The versions of these rules elements MUST NOT be different.
Depending on the data category and its usage, there are additional attributes for adding information to the selected nodes, or for pointing to existing information in the document. For example, the Localization Note data category can be used for adding notes to selected nodes, or for pointing to existing notes in the document. For the former purpose, a locNote element can be used. For the latter purpose, a locNotePointer attribute can be used.
Each data category allows you to add information to the selected nodes except for language information. Pointing to existing information is not possible for data categories that express a closed set of values, that is: Translate, Directionality and Elements Within Text.
The functionalities of adding information and pointing to existing information are mutually exclusive. That is: markup for pointing and adding MUST NOT appear in the same rule element.
Another difference between adding and pointing is the usage of XPath:
The value of the selector attribute MUST be an XPath expression
which starts with "/". That is, it must
be an
AbsoluteLocationPath as described in XPath 1.0 or its successor. This ensures that
the selection is not relative to a specific
location. The resulting nodes MUST be either element or
attribute nodes.
Attributes that point to existing information in the document, i.e. attributes whose name ends in ...Pointer, MUST use a RelativeLocationPath as described in XPath 1.0 or its successor. The XPath expression is evaluated relative to the nodes selected by the selector attribute. The following
attributes point to existing information: locNotePointer, locNoteRefPointer, termInfoPointer, termInfoRefPointer, rubyPointer, rtPointer, rpPointer, rbcPointer, rtcPointer, rbspanPointer, langPointer.
If namespaces [XML Names] are used in XPath expressions in the selector attribute or the pointing attributes, the following rules MUST be applied while processing XPath:
For each prefix, there MUST be an xmlns attribute at the same rule element which allows to resolve the namespace URI of the prefix.
Element and attribute names without a prefix are interpreted as having no namespace.
To avoid a conflict with rule 2., default namespaces MUST NOT be used in the XPath expressions.
The term element from the TEI is in a
namespace http://www.tei-c.org/ns/1.0.
<its:rules xmlns:its="http://www.w3.org/2005/11/its" xmlns:tei="http://www.tei-c.org/ns/1.0" version="1.0"> <its:termRule selector="//tei:term" term="yes"/> </its:rules>
[Source file: EX-selection-global-1.xml]
The qterm element from DocBook is in no
namespace.
<its:rules xmlns:its="http://www.w3.org/2005/11/its" version="1.0"> <its:termRule selector="//qterm" term="yes"/> </its:rules>
[Source file: EX-selection-global-2.xml]
Global rules can appear in the XML document they will be applied to, or in a separate XML document. The precedence of their processing depends on these variations. See also Section 5.4: Precedence between Selections.
Markup for global, rule-based selection is defined as follows.
| [1] | rules |
::= | element its:rules { rules.content, rules.attributes } |
| [2] | rules.content |
::= |
(
translateRule
| locNoteRule
| termRule
| dirRule
| rubyRule
| langRule
| withinTextRule
)* |
| [3] | rules.attributes |
::= |
attribute version { xsd:float },
attribute xlink:href { xsd:anyURI }?,
attribute xlink:type { "simple" }? |
| [4] | att.selector.attributes |
::= |
att.selector.attribute.selector
|
| [5] | att.selector.attribute.selector |
::= | attribute selector { string } |
| [6] | att.version.attributes |
::= |
att.version.attribute.version
|
| [7] | att.version.attribute.version |
::= | attribute its:version { xsd:float } |