Big Picture Changes

DocBook V5.0 is in the namespace http://docbook.org/ns/docbook.

A version attribute is now required on the root element.

Element and attribute names are case-sensitive (as they have been in the XML DTD since 4.0).

Content models are generally simpler.

Uses XLink; allows most inlines to be link elements.

Many constraints are now enforced by the grammar. They are not new, but they could not previously be enforced by DTDs.

A few simple datatypes are used.

Accessibility has been improved with the introduction of alt and annotation tags.