The bookmap feature

Bookmaps are a specialisation of the base DITA map information type. Like ditamaps, bookmaps are containers for structure and context metadata, and do not contain any content. Bookmaps are used to describe page layout publishing outputs such as books, articles, manuals and research papers. They contain information structures that are specific to linear publications, such as tables of figures, title pages, chapters, sections and parts.

The core DITA schema includes the ditamap format (or application), which is suitable for describing many collections of topics. However, for some book-style collections (such as a large, paper-based Reference Manual), the standard ditamap is inadequate. Like other DITA applications, ditamaps can be specialised to meet special needs.

A specialised ditamap, called bookmap, is now part of the base DITA specification. The bookmap is a specialisation of ditamap in the same way that concept is a specialisation of topic.

Bookmap is a specialisation of ditamap

The official definition of bookmap is:

The bookmap specialization of DITA's standard DITA map allows you to organize your DITA topics into a collection that can be printed as a book or other paged layout.
OASIS DITA Version 1.1 Architectural Specification

Bookmap allows you to produce DITA topics as the content of a "formally defined" book. A formally defined book means one with covers, formal notices, front matter (notices, acknowledgements, dedications, preface, etc), chapters, sections, parts, and back matter (notices, lists, etc). Bookmap is needed because the standard ditamap doesn't have structures for these book components.

A bookmap has the following major structures: