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Architectural specification: All-inclusive edition
The architectural specification portion of the DITA specification outlines the framework of DITA. It contains an overview of DITA markup; addressing; processing; configuration, specialization, generalization, and constraints; as well as information about coding DITA grammar files.
Coding practices for DITA grammar files
This section collects all of the rules for creating modular DTD, RELAX NG, or XML Schema grammar files to represent DITA document types, specializations, and constraints.
DTD coding requirements
This section explains how to implement DTD based document-type shells, specializations, and constraints.
DTD: Coding requirements for attribute domain modules
The vocabulary modules that define attribute domains have additional coding requirements. The module must include a parameter entity for the new attribute, which can be referenced in document-type shells, as well as a text entity that specifies the contribution to the @domains attribute for the attribute domain.

Specification URIs
Notices
Introduction to DITA 1.3
The Darwin Information Typing Architecture (DITA) specification defines a set of document types for authoring and organizing topic-oriented information, as well as a set of mechanisms for combining, extending, and constraining document types.
Architectural specification: All-inclusive edition
The architectural specification portion of the DITA specification outlines the framework of DITA. It contains an overview of DITA markup; addressing; processing; configuration, specialization, generalization, and constraints; as well as information about coding DITA grammar files.
- Introduction to DITA
  The Darwin Information Typing Architecture (DITA) is an XML-based architecture for authoring, producing, and delivering topic-oriented, information-typed content that can be reused and single-sourced in a variety of ways. While DITA historically has been driven by the requirements of large-scale technical documentation authoring, management, and delivery, it is a standard that is applicable to any kind of publication or information that might be presented to readers, including interactive training and educational materials, standards, reports, business documents, trade books, travel and nature guides, and more.
- DITA markup
  Topics and maps are the basic building blocks of the Darwin Information Typing Architecture (DITA). Metadata attributes and values can be added to DITA topics and maps, as well as to elements within topics, to allow for conditional publishing and content reuse.
- DITA addressing
  DITA provides two addressing mechanisms. DITA addresses either are direct URI-based addresses, or they are indirect key-based addresses. Within DITA documents, individual elements are addressed by unique identifiers specified on the @id attribute. DITA defines two fragment-identifier syntaxes; one is the full fragment-identifier syntax, and the other is an abbreviated fragment-identifier syntax that can be used when addressing non-topic elements from within the same topic.
- DITA processing
  DITA processing is affected by a number of factors, including attributes that indicate the set of vocabulary and constraint modules on which a DITA document depends; navigation; linking; content reuse (using direct or indirect addressing); conditional processing; branch filtering; chunking; and more. In addition, translation of DITA content is expedited through the use of the @dir, @translate, and @xml:lang attributes, and the <index-sort-as> element.
- Configuration, specialization, generalization, and constraints
  The extension facilities of DITA allow existing vocabulary and constraint modules to be combined to create specific DITA document types. Vocabulary modules also can be specialized to meet requirements that are not satisfied by existing markup.
- Coding practices for DITA grammar files
  This section collects all of the rules for creating modular DTD, RELAX NG, or XML Schema grammar files to represent DITA document types, specializations, and constraints.
  - Recognized XML-document grammar mechanisms
    The DITA standard recognizes three XML-document grammar mechanisms by which conforming DITA vocabulary modules and document types can be constructed: document type declarations (DTDs), XML Schema declarations (XSDs), and RELAX NG grammars.
  - Normative versions of DITA grammar files
    The OASIS DITA Technical Committee uses the RELAX NG XML syntax for the normative versions of the XML grammar files that comprise the DITA release.
  - DTD coding requirements
    This section explains how to implement DTD based document-type shells, specializations, and constraints.
    - DTD: Overview of coding requirements
      DITA coding practices for DTDs rely heavily on entities to implement specialization and constraints. As such, an understanding of entities is critical when working with DTD document-type shells, vocabulary modules, or constraint modules.
    - DTD: Coding requirements for document-type shells
      A DTD-based document-type shell is organized into sections; each section contains entity declarations that follow specific coding rules.
    - DTD: Coding requirements for element type declarations
      This topic covers general coding requirements for defining element types in both structural and element-domain vocabulary modules. In addition, it covers how to create the @domains attribute contribution for these modules.
    - DTD: Coding requirements for structural modules
      A structural vocabulary module defines a new topic or map type as a specialization of a topic or map type.
    - DTD: Coding requirements for element domain modules
      The vocabulary modules that define element domains have an additional coding requirement. The entity declaration file must include a parameter entity for each element that the domain extends.
    - DTD: Coding requirements for attribute domain modules
      The vocabulary modules that define attribute domains have additional coding requirements. The module must include a parameter entity for the new attribute, which can be referenced in document-type shells, as well as a text entity that specifies the contribution to the @domains attribute for the attribute domain.
    - DTD: Coding requirements for constraint modules
      A structural constraint module defines the constraints for a map or topic element type. A domain constraint module defines the constraints for an element or attribute domain.
  - RELAX NG coding requirements
    This section explains how to implement RELAX NG based document-type shells, specializations, and constraints.
  - XML Schema coding requirements
    This section explains how to implement XML Schema (XSD) based document-type shells, specializations, and constraints.
- Technical content specializations
  This section contains information about the technical content specializations. It includes a summary of the document types and domains, as well as information about how the technical content specializations support authoring troubleshooting information.
- Learning and training specializations
  The section contains information about the learning and training specializations: Challenges faced by developers of instructional content; use cases; objectives of the specializations; information about the reusable learning-objects approach to learning and training content; summary of the topic types and domains; and more.
Language reference: All-inclusive edition
The language reference portion of the DITA specification contains a topic for each DITA element. The topic defines the element, its inheritance hierarchy, and provides examples of usage. This portion of the DITA specification also includes information about DITA attributes.
Conformance
Conformance to the DITA specification allows documents and document types that are used with different processors or different versions of a processor to produce the same or similar results with little or no reimplementation or modification.
Acknowledgments
(Non-normative) Many members of the OASIS DITA Technical Committee participated in the creation of this specification and are gratefully acknowledged.
Non-normative information
This section contains non-normative information, including topics about new features in DITA 1.3 and migrating from DITA 1.2 to DITA 1.3.
Content models for learning and training package
For each element in the learning and training package, this section presents the content model and a list of parent elements that can contain that element.

DTD: Coding requirements for attribute domain modules

The vocabulary modules that define attribute domains have additional coding requirements. The module must include a parameter entity for the new attribute, which can be referenced in document-type shells, as well as a text entity that specifies the contribution to the @domains attribute for the attribute domain.

An attribute domain's name is the name of the attribute plus "Att". For example, for the attribute named "deliveryTarget" the attribute domain name is "deliveryTargetAtt". The attribute domain name is used to construct entity names for the domain.

Parameter entity name and value: The name of the parameter entity is the attribute domain name, followed by the literal "-d-attribute". The value of the parameter entity is a DTD declaration for the attribute.
Text entity name and value: The text entity name is the attribute domain name, followed by the literal -d-Att. The value of the text entity is the @domains attribute contribution for the module; see domains attribute rules and syntax for details on how to construct this value.

Example

The @deliveryTarget attribute can be defined in a vocabulary module using the following two entities.

<!ENTITY % deliveryTargetAtt-d-attribute
  "deliveryTarget  CDATA  #IMPLIED"
>

<!ENTITY deliveryTargetAtt-d-att "a(props deliveryTarget)" >