One of the early factors that motivated the development of DocBook was the desire for companies to interchange documents. In particular, UNIX vendors wanted to be able to interchange common UNIX documentation.
A great deal of effort went into making sure that DocBook could handle most (probably all) of the documents that were likely to be exchanged. This avoids the guaranteed problem of interchanging documents created with extended schemas.
However, simply using DocBook or a subset of it is not enough to ensure successful interchange. If you send someone your DocBook files, you must also tell the recipient about the markup your documents use, any additional markup conventions, and any processing expectations that impose constraints.
This appendix provides a sample interchange questionnaire to help draw your attention to those areas that might cause problems.
For maximum portability, delivered DocBook documents should be accompanied by a filled-out interchange questionnaire. Because each situation is unique, you may need to supply additional information (such as layout specifications) in order to deliver a complete package.
What version of the schema are you using?
Did you use any markup features of the schema that have been flagged as obsolete (to be removed at the next major version of DocBook)? If so, which ones?
Did you extend DocBook in any way, inside or outside the provided customization mechanisms? How? All extensions ...