DITA 2.0 preview support

DITA Open Toolkit 3.6 provides a preview of features for the upcoming OASIS DITA 2.0 specification. This preliminary processing support is provided on the basis of the latest DRAFT versions of the DITA 2.0 DTD and RELAX NG grammar files from OASIS (as of October 2020).

DITA documents that reference the draft grammar files can be parsed, and where features overlap with DITA 1.3, those features will work as expected.


DITA-OT 3.5 provided an initial preview of DITA 2.0 features.

  • The new <include> element can be used to reference text or XML content from other files. In addition to the processing mandated by the specification, DITA-OT also supports the character set definition and line range extraction options previously provided for <coderef> elements (see Extended codeblock processing).

  • The new @specializations attribute, which replaces the DITA 1.x @domains attribute, can now be used as an alternative method of declaring specialized attributes.

  • The @outputclass attribute can now be specified as a flagging behavior in DITAVAL files. This allows you to flag an element with a CSS class keyword that will be added to the @class attribute value in the generated HTML. Output classes allow you to pick up pre-defined styles from existing web frameworks, and are more easily overridden with custom CSS files than the inline @style attributes generated by DITA 1.x flagging options such as @color and @backcolor.

  • Titles can now be specified on simple tables, and <simpletable> entries now support row and column spanning attributes.

  • Where DITA 1.x defined conflicting @class values for <linktext>, <shortdesc>, and <searchtitle> in maps and topics, the new draft of DITA 2.0 uses the topic-based @class value in all cases. Processing is updated to recognize the updated value when these elements are used in maps.


DITA-OT 3.6 adds support for additional DITA 2.0 features.

  • Where earlier DITA versions relied on the <object> to embed media in DITA source files, DITA 2.0 provides new <audio> and <video> elements that correspond to their HTML5 equivalents.
  • For HTML5 compatibility, the new emphasis domain adds support for the <strong> and <em> elements in addition to the existing <b> and <i> elements in the highlighting domain.
  • The troubleshooting domain has been updated with additional constructs that can be used to provide detailed diagnostic information.
  • Several obsolete elements and attributes have been removed from DITA 2.0, including:
    • <boolean>
    • <data-about>
    • <indextermref>
    • @alt on <image>
    • @navtitle on <topicref>
    • @query on <topicref>
    • @refcols on <simpletable>
    • @xtrc
    • @xtrf
Note: Other new or revised features proposed for DITA 2.0 are not yet supported. Additional features will be implemented in future versions of DITA-OT as the specification evolves.
Tip: For the latest status information on DITA 2.0-related features and fixes, see the DITA 2.0 label in the GitHub issues tracker.