My research shows that the catalog.xml file that ships with the DocBook 5.1 schemas is listed as one of the work products in the OASIS Standard, and so it is part of the Standard. That will require we do an Errata for 5.1. I will also be suggested a couple of changes to the assembly schema as well, so we can do those in one Errata for 5.1 Stay tuned. -- Bob Stayton Sagehill Enterprises
bobs@sagehill.net