DocBook Publishers: The Definitive Guide (Version 1.2.1 for DocBook 5.1)
Preface to the DocBook V5.1 Edition
This edition of DocBook Publishers: The Definitive Guide describes the DocBook V5.1 schema, currently version UNKNOWN.
If you're using DocBook Publishers V1.0, you will find some things in this online text which are new or different from the OASIS Standard release.
Please see DocBook 5.1: The Definitive Guide for more details.