DocBook V4.1 and DocBook XML V4.1.2

DocBook V4.1 and DocBook XML V4.1.2 became an OASIS Standard in February 2001.

DocBook V4 introduced a number of backward-incompatible changes.

The policy of the DocBook TC is that backward-incompatible changes can only be introduced in a full version release. They must also be described in comments in the DTD at least one full version earlier. In other words, all the planned version 4.0 incompatibilities were announced with version 3.0.

Backward-incompatible changes to DocBook that are planned for version 4.0: