embedding DocBook in another schema

Hi, new to the list, hope this is appropriate.

I have a fairly simple schema in Relax NG that basically describes 
steps in a process.  STEPs have ACTIONs with OUTPUTs etc.

What I'm trying to do is allow any valid DocBook markup withing a 
DESCRIPTION element.

I've got as far as

{include href=".../docbook.rng" ns="http://docbook.ns/"}

(replace curly with angle brackets of course)

but the problems are

a) duplicate start blocks, and

b) when I "fix" (a) by commenting out the start block in 
.../docbook.rng I get duplicate element definitions (e.g. DocBook 
also has a step element).

I was hoping all the DocBook stuff would be in the (made up) 
http://docbook.ns/ namespace, is that what ns does?

How is this supposed to work?

Note that it's getting the DocBook grammar to include in my grammar 
that I'm having trouble with, not defining a DESCRIPTION element 
that can contain any DocBook content (which I haven't tried yet).

Ugly details:

I'm using trang to make .rnc files and feeding them to nxml-mode in 
emacs.  So it's really the start block in the .../docbook.rnc file 
I'm commenting out.

Thanks for any pointers.

-----------------------------------------------------------------------
Terry Brown               Natural Resources Research Institute
Research Associate        5013 Miller Trunk Highway
[email protected]       University of Minnesota, Duluth
Ph. 218 720 4345          Duluth, Minnesota 55811
Fax 218 720 4328          http://beaver.nrri.umn.edu/~tbrown/