bookmap or ditamap?

I'm looking for some good reasons why you would want to use a bookmap instead of a ditamap.

Obviously, you use a bookmap if you wish to "to produce your DITA topics and even whole DITA maps as the content of a formally defined book. This allows you to produce not only maps for online deliverables, but also PDFs with the same content, replete with covers, formal notices and frontmatter, and so forth." (Source: DITA Architectural Specification v1.1).

However, when I generate PDF output from a ditamap, I can get covers, front matter (TOC) and back matter (index, glossary) as well (using XMetaL or oXygen). And when I use DITA-FMx, I can add a cover, frontmatter (TOC), backmatter (index, glossary) and any other "unstructured" or "generated" FM files to my (generated) FM book.

The only reasons for using a bookmap I'm seeing at this moment are:
  • You really want to have the "bookmeta" information, front matter and back matter in DITA XML format
  • You need to have the "traditional" book structures and sections: part, chapter, appendix

Any others?

Thanks.


--
Yves Barbion
www.scripto.nu
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