Currently the chunked, multi-page, docbook uses indexed numbers for
pages. These numbers can change from build to build as the content
changes. It seems that chunking can accept various attributes for the
url name. This means if someone takes the time to update the docbook we
can get something close to permanlinks. If we have links that don't
change too often people can then use those web annotation systems, to
allow live annotations and comments.
http://www.sagehill.net/docbookxsl/Chunking.html
Mark