Darwin Information Typing Architecture (DITA) Version 1.3 Part 1: Base Edition

Chapter 1: Introduction to DITA 1.3
- 1.1.1: About the DITA specification: Base edition
- 1.1.2: Terminology
- 1.1.3: Normative references
- 1.1.4: Non-normative references
- 1.1.5: Formatting conventions in the XHTML version of the specification
Chapter 2: Architectural Specification: Base edition
- 2.2.1: Introduction to DITA
  - 2.2.1.1: DITA terminology and notation
  - 2.2.1.2: Basic concepts
  - 2.2.1.3: File extensions
  - 2.2.1.4: Producing different deliverables from a single source
- 2.2.2: DITA markup
  - 2.2.2.1: DITA topics
    - 2.2.2.1.1: The topic as the basic unit of information
    - 2.2.2.1.2: The benefits of a topic-based architecture
    - 2.2.2.1.3: Disciplined, topic-oriented writing
    - 2.2.2.1.4: Information typing
    - 2.2.2.1.5: Generic topics
    - 2.2.2.1.6: Topic structure
    - 2.2.2.1.7: Topic content
  - 2.2.2.2: DITA maps
    - 2.2.2.2.1: Definition of DITA maps
    - 2.2.2.2.2: Purpose of DITA maps
    - 2.2.2.2.3: DITA map elements
    - 2.2.2.2.4: DITA map attributes
    - 2.2.2.2.5: Examples of DITA maps
      - 2.2.2.2.5.1: Example: DITA map that references a subordinate map
      - 2.2.2.2.5.2: Example: DITA map with a simple relationship table
      - 2.2.2.2.5.3: Example: How the @collection-type and @linking attributes determine links
      - 2.2.2.2.5.4: Example: How the @cascade attribute functions
  - 2.2.2.3: Subject scheme maps and their usage
    - 2.2.2.3.1: Subject scheme maps
    - 2.2.2.3.2: Defining controlled values for attributes
    - 2.2.2.3.3: Binding controlled values to an attribute
    - 2.2.2.3.4: Processing controlled attribute values
    - 2.2.2.3.5: Extending subject schemes
    - 2.2.2.3.6: Scaling a list of controlled values to define a taxonomy
    - 2.2.2.3.7: Classification maps
    - 2.2.2.3.8: Examples of subject scheme maps
      - 2.2.2.3.8.1: Example: How hierarchies defined in a subject scheme map affect filtering
      - 2.2.2.3.8.2: Example: Extending a subject scheme
      - 2.2.2.3.8.3: Example: Extending a subject scheme upwards
      - 2.2.2.3.8.4: Example: Defining values for @deliveryTarget
  - 2.2.2.4: DITA metadata
    - 2.2.2.4.1: Metadata elements
    - 2.2.2.4.2: Metadata attributes
      - 2.2.2.4.2.1: Conditional processing attributes
      - 2.2.2.4.2.2: Translation and localization attributes
      - 2.2.2.4.2.3: Architectural attributes
    - 2.2.2.4.3: Metadata in maps and topics
    - 2.2.2.4.4: Cascading of metadata attributes in a DITA map
    - 2.2.2.4.5: Reconciling topic and map metadata elements
    - 2.2.2.4.6: Map-to-map cascading behaviors
      - 2.2.2.4.6.1: Cascading of attributes from map to map
      - 2.2.2.4.6.2: Cascading of metadata elements from map to map
      - 2.2.2.4.6.3: Cascading of roles from map to map
    - 2.2.2.4.7: Context hooks and window metadata for user assistance
- 2.2.3: DITA addressing
  - 2.2.3.1: ID attribute
  - 2.2.3.2: DITA linking
  - 2.2.3.3: URI-based (direct) addressing
  - 2.2.3.4: Indirect key-based addressing
    - 2.2.3.4.1: Core concepts for working with keys
    - 2.2.3.4.2: Key scopes
    - 2.2.3.4.3: Using keys for addressing
    - 2.2.3.4.4: Addressing keys across scopes
    - 2.2.3.4.5: Cross-deliverable addressing and linking
    - 2.2.3.4.6: Processing key references
    - 2.2.3.4.7: Processing key references for navigation links and images
    - 2.2.3.4.8: Processing key references on <topicref> elements
    - 2.2.3.4.9: Processing key references to generate text or link text
    - 2.2.3.4.10: Examples of keys
      - 2.2.3.4.10.1: Examples: Key definition
      - 2.2.3.4.10.2: Examples: Key definitions for variable text
      - 2.2.3.4.10.3: Example: Scoped key definitions for variable text
      - 2.2.3.4.10.4: Example: Duplicate key definitions within a single map
      - 2.2.3.4.10.5: Example: Duplicate key definitions across multiple maps
      - 2.2.3.4.10.6: Example: Key definition with key reference
      - 2.2.3.4.10.7: Example: References to scoped keys
      - 2.2.3.4.10.8: Example: Key definitions in nested key scopes
      - 2.2.3.4.10.9: Example: Link redirection
      - 2.2.3.4.10.10: Example: Link modification or removal
      - 2.2.3.4.10.11: Example: Links from <term> or <keyword> elements
      - 2.2.3.4.10.12: Example: conref redirection
      - 2.2.3.4.10.13: Example: Key scopes and omnibus publications
      - 2.2.3.4.10.14: Example: How key scopes affect key precedence
      - 2.2.3.4.10.15: Example: Keys and collaboration
- 2.2.4: DITA processing
  - 2.2.4.1: Navigation
    - 2.2.4.1.1: Table of contents
    - 2.2.4.1.2: Indexes
  - 2.2.4.2: Content reference (conref)
    - 2.2.4.2.1: Conref overview
    - 2.2.4.2.2: Processing conrefs
    - 2.2.4.2.3: Processing attributes when resolving conrefs
    - 2.2.4.2.4: Processing xrefs and conrefs within a conref
  - 2.2.4.3: Conditional processing (profiling)
    - 2.2.4.3.1: Conditional processing values and groups
    - 2.2.4.3.2: Filtering
    - 2.2.4.3.3: Flagging
    - 2.2.4.3.4: Conditional processing to generate multiple deliverable types
    - 2.2.4.3.5: Examples of conditional processing
      - 2.2.4.3.5.1: Example: Setting conditional processing values and groups
      - 2.2.4.3.5.2: Example: Filtering and flagging topic content
  - 2.2.4.4: Branch filtering
    - 2.2.4.4.1: Overview of branch filtering
    - 2.2.4.4.2: Branch filtering: Single condition set for a branch
    - 2.2.4.4.3: Branch filtering: Multiple condition sets for a branch
    - 2.2.4.4.4: Branch filtering: Impact on resource and key names
    - 2.2.4.4.5: Branch filtering: Implications of processing order
    - 2.2.4.4.6: Examples of branch filtering
      - 2.2.4.4.6.1: Example: Single <ditavalref> on a branch
      - 2.2.4.4.6.2: Example: Multiple <ditavalref> elements on a branch
      - 2.2.4.4.6.3: Example: Single <ditavalref> as a child of <map>
      - 2.2.4.4.6.4: Example: Single <ditavalref> in a reference to a map
      - 2.2.4.4.6.5: Example: Multiple <ditavalref> elements as children of <map> in a root map
      - 2.2.4.4.6.6: Example: Multiple <ditavalref> elements in a reference to a map
      - 2.2.4.4.6.7: Example: <ditavalref> within a branch that already uses <ditavalref>
      - 2.2.4.4.6.8: Example: <ditavalref> error conditions
  - 2.2.4.5: Chunking
    - 2.2.4.5.1: Using the @chunk attribute
    - 2.2.4.5.2: Chunking examples
  - 2.2.4.6: Translation and localization
    - 2.2.4.6.1: The @xml:lang attribute
    - 2.2.4.6.2: The @dir attribute
  - 2.2.4.7: Processing documents with different values of the @domains attribute
  - 2.2.4.8: Sorting
- 2.2.5: Configuration, specialization, generalization, and constraints
  - 2.2.5.1: Overview of DITA extension facilities
  - 2.2.5.2: Configuration
    - 2.2.5.2.1: Overview of document-type shells
    - 2.2.5.2.2: Rules for document-type shells
    - 2.2.5.2.3: Equivalence of document-type shells
    - 2.2.5.2.4: Conformance of document-type shells
  - 2.2.5.3: Specialization
    - 2.2.5.3.1: Overview of specialization
    - 2.2.5.3.2: Modularization
    - 2.2.5.3.3: Vocabulary modules
    - 2.2.5.3.4: Specialization rules for element types
    - 2.2.5.3.5: Specialization rules for attributes
    - 2.2.5.3.6: @class attribute rules and syntax
    - 2.2.5.3.7: @domains attribute rules and syntax
    - 2.2.5.3.8: Specializing to include non-DITA content
    - 2.2.5.3.9: Sharing elements across specializations
  - 2.2.5.4: Generalization
    - 2.2.5.4.1: Overview of generalization
    - 2.2.5.4.2: Element generalization
    - 2.2.5.4.3: Processor expectations when generalizing elements
    - 2.2.5.4.4: Attribute generalization
    - 2.2.5.4.5: Generalization with cross-specialization dependencies
  - 2.2.5.5: Constraints
    - 2.2.5.5.1: Overview of constraints
    - 2.2.5.5.2: Constraint rules
    - 2.2.5.5.3: Constraints, processing, and interoperability
    - 2.2.5.5.4: Weak and strong constraints
    - 2.2.5.5.5: Conref compatibility with constraints
    - 2.2.5.5.6: Examples: Constraints
      - 2.2.5.5.6.1: Example: Redefine the content model for the <topic> element
      - 2.2.5.5.6.2: Example: Constrain attributes for the <section> element
      - 2.2.5.5.6.3: Example: Constrain a domain module
      - 2.2.5.5.6.4: Example: Replace a base element with the domain extensions
      - 2.2.5.5.6.5: Example: Apply multiple constraints to a single document-type shell
- 2.2.6: Coding practices for DITA grammar files
  - 2.2.6.1: Recognized XML-document grammar mechanisms
  - 2.2.6.2: Normative versions of DITA grammar files
  - 2.2.6.3: DTD coding requirements
    - 2.2.6.3.1: DTD: Overview of coding requirements
    - 2.2.6.3.2: DTD: Coding requirements for document-type shells
    - 2.2.6.3.3: DTD: Coding requirements for element type declarations
    - 2.2.6.3.4: DTD: Coding requirements for structural modules
    - 2.2.6.3.5: DTD: Coding requirements for element domain modules
    - 2.2.6.3.6: DTD: Coding requirements for attribute domain modules
    - 2.2.6.3.7: DTD: Coding requirements for constraint modules
  - 2.2.6.4: RELAX NG coding requirements
    - 2.2.6.4.1: RELAX NG: Overview of coding requirements
    - 2.2.6.4.2: RELAX NG: Coding requirements for document-type shells
    - 2.2.6.4.3: RELAX NG: Coding requirements for element type declarations
    - 2.2.6.4.4: RELAX NG: Coding requirements for structural modules
    - 2.2.6.4.5: RELAX NG: Coding requirements for element domain modules
    - 2.2.6.4.6: RELAX NG: Coding requirements for attribute domain modules
    - 2.2.6.4.7: RELAX NG: Coding requirements for constraint modules
  - 2.2.6.5: XML Schema coding requirements
    - 2.2.6.5.1: XML Schema: Overview and limitations of coding requirements
    - 2.2.6.5.2: XML Schema: Coding requirements for document-type shells
    - 2.2.6.5.3: XML Schema: Coding requirements for element type declarations
    - 2.2.6.5.4: XML Schema: Coding requirements for structural modules
    - 2.2.6.5.5: XML Schema: Coding requirements for attribute domain modules
    - 2.2.6.5.6: XML Schema: Coding requirements for constraint modules
Chapter 3: Language Reference: Base edition
- 3.3.1: Base DITA elements, A to Z
- 3.3.2: Topic elements
  - 3.3.2.1: Basic topic elements
    - 3.3.2.1.1: <topic>
    - 3.3.2.1.2: <title>
    - 3.3.2.1.3: <titlealts>
    - 3.3.2.1.4: <searchtitle>
    - 3.3.2.1.5: <navtitle>
    - 3.3.2.1.6: <shortdesc>
    - 3.3.2.1.7: <abstract>
    - 3.3.2.1.8: <body>
    - 3.3.2.1.9: <bodydiv>
    - 3.3.2.1.10: <related-links>
    - 3.3.2.1.11: <dita>
  - 3.3.2.2: Body elements
    - 3.3.2.2.1: <alt>
    - 3.3.2.2.2: <cite>
    - 3.3.2.2.3: <dd>
    - 3.3.2.2.4: <desc>
    - 3.3.2.2.5: <ddhd>
    - 3.3.2.2.6: <div>
    - 3.3.2.2.7: <dl>
    - 3.3.2.2.8: <dlentry>
    - 3.3.2.2.9: <dlhead>
    - 3.3.2.2.10: <dt>
    - 3.3.2.2.11: <draft-comment>
    - 3.3.2.2.12: <dthd>
    - 3.3.2.2.13: <example>
    - 3.3.2.2.14: <fig>
    - 3.3.2.2.15: <figgroup>
    - 3.3.2.2.16: <fn>
    - 3.3.2.2.17: <image>
    - 3.3.2.2.18: <keyword>
    - 3.3.2.2.19: <li>
    - 3.3.2.2.20: <lines>
    - 3.3.2.2.21: <longdescref>
    - 3.3.2.2.22: <longquoteref>
    - 3.3.2.2.23: <lq>
    - 3.3.2.2.24: <note>
    - 3.3.2.2.25: <object>
    - 3.3.2.2.26: <ol>
    - 3.3.2.2.27: <p>
    - 3.3.2.2.28: <param>
    - 3.3.2.2.29: <ph>
    - 3.3.2.2.30: <pre>
    - 3.3.2.2.31: <q>
    - 3.3.2.2.32: <section>
    - 3.3.2.2.33: <sectiondiv>
    - 3.3.2.2.34: <sl>
    - 3.3.2.2.35: <sli>
    - 3.3.2.2.36: <term>
    - 3.3.2.2.37: <text>
    - 3.3.2.2.38: <tm>
    - 3.3.2.2.39: <ul>
    - 3.3.2.2.40: <xref>
  - 3.3.2.3: Table elements
    - 3.3.2.3.1: <table>
    - 3.3.2.3.2: <tgroup>
    - 3.3.2.3.3: <colspec>
    - 3.3.2.3.4: <thead>
    - 3.3.2.3.5: <tbody>
    - 3.3.2.3.6: <row>
    - 3.3.2.3.7: <entry>
    - 3.3.2.3.8: <simpletable>
    - 3.3.2.3.9: <sthead>
    - 3.3.2.3.10: <strow>
    - 3.3.2.3.11: <stentry>
  - 3.3.2.4: Related links elements
    - 3.3.2.4.1: <link>
    - 3.3.2.4.2: <linklist>
    - 3.3.2.4.3: <linkpool>
    - 3.3.2.4.4: <linktext>
    - 3.3.2.4.5: <linkinfo>
- 3.3.3: Map elements
  - 3.3.3.1: Basic map elements
    - 3.3.3.1.1: <map>
    - 3.3.3.1.2: <topicref>
    - 3.3.3.1.3: <topicmeta>
    - 3.3.3.1.4: <anchor>
    - 3.3.3.1.5: <navref>
    - 3.3.3.1.6: <reltable>
    - 3.3.3.1.7: <relrow>
    - 3.3.3.1.8: <relcell>
    - 3.3.3.1.9: <relheader>
    - 3.3.3.1.10: <relcolspec>
    - 3.3.3.1.11: <ux-window>
  - 3.3.3.2: Map group elements
    - 3.3.3.2.1: <anchorref>
    - 3.3.3.2.2: <keydef>
    - 3.3.3.2.3: <mapref>
    - 3.3.3.2.4: <topicgroup>
    - 3.3.3.2.5: <topichead>
    - 3.3.3.2.6: <topicset>
    - 3.3.3.2.7: <topicsetref>
- 3.3.4: Metadata elements
  - 3.3.4.1: Prolog (metadata) elements
    - 3.3.4.1.1: <prolog>
    - 3.3.4.1.2: <audience>
    - 3.3.4.1.3: <author>
    - 3.3.4.1.4: <brand>
    - 3.3.4.1.5: <category>
    - 3.3.4.1.6: <component>
    - 3.3.4.1.7: <copyright>
    - 3.3.4.1.8: <copyrholder>
    - 3.3.4.1.9: <copyryear>
    - 3.3.4.1.10: <created>
    - 3.3.4.1.11: <critdates>
    - 3.3.4.1.12: <featnum>
    - 3.3.4.1.13: <keywords>
    - 3.3.4.1.14: <metadata>
    - 3.3.4.1.15: <othermeta>
    - 3.3.4.1.16: <permissions>
    - 3.3.4.1.17: <platform>
    - 3.3.4.1.18: <prodinfo>
    - 3.3.4.1.19: <prodname>
    - 3.3.4.1.20: <prognum>
    - 3.3.4.1.21: <publisher>
    - 3.3.4.1.22: <resourceid>
    - 3.3.4.1.23: <revised>
    - 3.3.4.1.24: <series>
    - 3.3.4.1.25: <source>
    - 3.3.4.1.26: <vrmlist>
    - 3.3.4.1.27: <vrm>
  - 3.3.4.2: Indexing group elements
    - 3.3.4.2.1: <indexterm>
    - 3.3.4.2.2: <indextermref>
    - 3.3.4.2.3: <index-see>
    - 3.3.4.2.4: <index-see-also>
    - 3.3.4.2.5: <index-sort-as>
  - 3.3.4.3: Delayed conref resolution elements
    - 3.3.4.3.1: <exportanchors>
    - 3.3.4.3.2: <anchorid>
    - 3.3.4.3.3: <anchorkey>
- 3.3.5: Domain elements
  - 3.3.5.1: Hazard statement elements
    - 3.3.5.1.1: <hazardstatement>
    - 3.3.5.1.2: <consequence>
    - 3.3.5.1.3: <hazardsymbol>
    - 3.3.5.1.4: <howtoavoid>
    - 3.3.5.1.5: <messagepanel>
    - 3.3.5.1.6: <typeofhazard>
  - 3.3.5.2: Highlighting elements
    - 3.3.5.2.1: <b>
    - 3.3.5.2.2: <i>
    - 3.3.5.2.3: <sup>
    - 3.3.5.2.4: <sub>
    - 3.3.5.2.5: <tt>
    - 3.3.5.2.6: <u>
    - 3.3.5.2.7: <line-through>
    - 3.3.5.2.8: <overline>
  - 3.3.5.3: Utilities elements
    - 3.3.5.3.1: <area>
    - 3.3.5.3.2: <coords>
    - 3.3.5.3.3: <imagemap>
    - 3.3.5.3.4: <shape>
    - 3.3.5.3.5: <sort-as>
  - 3.3.5.4: DITAVAL reference domain
    - 3.3.5.4.1: <ditavalref>
    - 3.3.5.4.2: <ditavalmeta>
    - 3.3.5.4.3: <dvrResourcePrefix>
    - 3.3.5.4.4: <dvrResourceSuffix>
    - 3.3.5.4.5: <dvrKeyscopePrefix>
    - 3.3.5.4.6: <dvrKeyscopeSuffix>
- 3.3.6: Classification elements
  - 3.3.6.1: Subject scheme elements
    - 3.3.6.1.1: <subjectScheme>
    - 3.3.6.1.2: <schemeref>
    - 3.3.6.1.3: <hasInstance>
    - 3.3.6.1.4: <hasKind>
    - 3.3.6.1.5: <hasNarrower>
    - 3.3.6.1.6: <hasPart>
    - 3.3.6.1.7: <hasRelated>
    - 3.3.6.1.8: <enumerationdef>
    - 3.3.6.1.9: <elementdef>
    - 3.3.6.1.10: <attributedef>
    - 3.3.6.1.11: <defaultSubject>
    - 3.3.6.1.12: <subjectHead>
    - 3.3.6.1.13: <subjectHeadMeta>
    - 3.3.6.1.14: <subjectdef>
    - 3.3.6.1.15: <relatedSubjects>
    - 3.3.6.1.16: <subjectRelTable>
    - 3.3.6.1.17: <subjectRelHeader>
    - 3.3.6.1.18: <subjectRel>
    - 3.3.6.1.19: <subjectRole>
  - 3.3.6.2: Classification domain elements
    - 3.3.6.2.1: <subjectref>
    - 3.3.6.2.2: <topicapply>
    - 3.3.6.2.3: <topicsubject>
    - 3.3.6.2.4: <topicSubjectTable>
    - 3.3.6.2.5: <topicSubjectHeader>
    - 3.3.6.2.6: <topicSubjectRow>
    - 3.3.6.2.7: <topicCell>
    - 3.3.6.2.8: <subjectCell>
- 3.3.7: Specialization elements
  - 3.3.7.1: <boolean>
  - 3.3.7.2: <data>
  - 3.3.7.3: <data-about>
  - 3.3.7.4: <foreign>
  - 3.3.7.5: <index-base>
  - 3.3.7.6: <itemgroup>
  - 3.3.7.7: <no-topic-nesting>
  - 3.3.7.8: <state>
  - 3.3.7.9: <unknown>
- 3.3.8: Legacy conversion elements
  - 3.3.8.1: <required-cleanup>
- 3.3.9: DITAVAL elements
  - 3.3.9.1: <val>
  - 3.3.9.2: <style-conflict>
  - 3.3.9.3: <prop>
  - 3.3.9.4: <revprop>
  - 3.3.9.5: <startflag>
  - 3.3.9.6: <endflag>
  - 3.3.9.7: <alt-text>
- 3.3.10: Attributes
  - 3.3.10.1: Universal attribute group
    - 3.3.10.1.1: ID attribute group
    - 3.3.10.1.2: Metadata attribute group
    - 3.3.10.1.3: Localization attribute group
    - 3.3.10.1.4: Debug attribute group
  - 3.3.10.2: Architectural attribute group
  - 3.3.10.3: Attributes common to many map elements
  - 3.3.10.4: Complex-table attribute group
  - 3.3.10.5: Data element attributes group
  - 3.3.10.6: Date attributes group
  - 3.3.10.7: Display attribute group
  - 3.3.10.8: Link relationship attribute group
  - 3.3.10.9: Other common attributes
  - 3.3.10.10: Simpletable attribute group
  - 3.3.10.11: Specialization attributes group
  - 3.3.10.12: Topicref element attributes group
  - 3.3.10.13: Complex attribute definitions
    - 3.3.10.13.1: The @href attribute
    - 3.3.10.13.2: The @keys attribute
    - 3.3.10.13.3: The @keyref attribute
    - 3.3.10.13.4: The @keyscope attribute
    - 3.3.10.13.5: The @conref attribute
      - 3.3.10.13.5.1: Using the -dita-use-conref-target value
    - 3.3.10.13.6: The @conaction attribute
    - 3.3.10.13.7: The @conrefend attribute
    - 3.3.10.13.8: The @conkeyref attribute
    - 3.3.10.13.9: The @type attribute
    - 3.3.10.13.10: The @format attribute
    - 3.3.10.13.11: The @scope attribute
    - 3.3.10.13.12: The @role and @otherrole attributes
Chapter 4: Conformance
Appendix A: Acknowledgments
Appendix B: Non-normative information
Appendix C: Content models: Base edition
- C.7.1 A elements
- C.7.2 B elements
- C.7.3 C elements
- C.7.4 D elements
- C.7.5 E elements
- C.7.6 F elements
- C.7.7 H elements
- C.7.8 I elements
- C.7.9 K elements
- C.7.10 L elements
- C.7.11 M elements
- C.7.12 N elements
- C.7.13 O elements
- C.7.14 P elements
- C.7.15 Q elements
- C.7.16 R elements
- C.7.17 S elements
- C.7.18 T elements
- C.7.19 U elements
- C.7.20 V elements
- C.7.21 X elements

Processing conrefs

When processing content references, DITA processors compare the restrictions of each context to ensure that the conrefed content is valid in its new context.

Except where allowed by weak constraints, a conref processor MUST NOT permit resolution of a reuse relationship that could be rendered invalid under the rules of either the reused or reusing content.

Note

The DITA @conref attribute is a transclusion mechanism similar to XInclude and to HyTime value references. DITA differs from these mechanisms, however, in that conref validity does not apply simply to the current content at the time of replacement, but to the possible content given the restrictions of both the referencing document type and the referenced document type.

When pulling content with the conref mechanism, if the referenced element is the same type as the referencing element, and the set of domains declared on the @domains attribute in the referenced topic or map instance is the same as or a subset of the domains declared in the referencing document, the element set allowed in the referenced element is guaranteed to be the same as, or a subset of, the element set allowed in the referencing element.

When pushing content with the conref mechanism, the domain checking algorithm is reversed. In this case, if the set of domains declared on the @domains attribute in the referencing topic or map instance is the same as or a subset of the domains declared in the referenced document, the element set allowed in the pushed content is guaranteed to be the same as, or a subset of, the element set allowed in the new location.

In both cases, processors resolving conrefs SHOULD tolerate specializations of valid elements and generalize elements in the pushed or pulled content fragment as needed for the resolving context.

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