This is not the current TREX Schema for DocBook. Please use TREX Schema V4.1.2.2 instead.
This version is available as a zip archive.
You can also retrieve the files individually if you prefer:
The DocBook TREX Schema.
The DocBook TREX Schema “hierarchy” module.
The DocBook TREX Schema “information pool” module.
The DocBook TREX Schema tables module.
A test document.