Migrating to release 4.4

DITA-OT 4.4 includes support for additional features in the upcoming DITA 2.0 standard, including the <keytext> and <linktitle> elements, new class attributes for <navtitle>, and new chunking code.

Note:
This topic provides a summary of changes in DITA-OT 4.4 that may require modifications to custom stylesheets or plug-ins. For more information on changes in this release, see the DITA-OT 4.4 Release Notes.

Preview DITA 2.0 updates

In addition to the DITA 2.0 preview support provided in DITA-OT 3.5 – 4.3, this release includes updated processing for the latest draft versions of the DITA 2.0 grammar files from OASIS (as of January 25, 2026).

Tip:
Consider updating your documents and/or customizations to take advantage of the new features and prepare for the transition to DITA 2.0.

Simple chunking cases in DITA 1.x maps can now be processed using the DITA 2.0 chunking module in compatibility mode. For example, a DITA 1.3 map with chunk="to-content" is now processed as if it used the DITA 2.0 chunk="combine" action. This refactoring improves reliability by leveraging the newer chunking code, which has fewer bugs than the legacy implementation. Note that this may change how splitting operations generate file names. #4600

The DITAVAL @outputclass attribute has been renamed to @add-outputclass to match the DITA 2.0 specification. Support for the old attribute name is retained for backwards compatibility, but a DOTA014W warning message is now generated when the deprecated @outputclass attribute is used. #4635

DITA-OT now supports the DITA 2.0 <keytext> element and implements the updated DITA 2.0 rules for generating key variable text. #4644

DITA-OT now supports the DITA 2.0 <linktitle> element and recognizes both the DITA 1.3 and DITA 2.0 class attributes for <navtitle>. When using a DITA 2.0 root map, the preprocessed map will contain both <linktext> (for DITA 1.3 compatibility) and <linktitle> (for DITA 2.0) elements. Plug-ins that handle <navtitle> or <linktext> may need to be updated to handle these new elements. #4734

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.