DocBook5: Offical URI used for customization in include?

[Thomas Schraitle <tom_schr@web.de>]

Hi,

I am wondering if there is an "official URI" for DocBook 5, especially for 
using it inside an include element.

Consider someone is customizing DocBook 5 and want to include the RELAX NG 
Schema:

  include "docbook.rnc" { ... }
           ^^^^^^^^^^^

Sometimes I see a path here which I consider bad style because it is 
platform dependend. How can I reference to the DocBook 5 Schema 
officially? Are there any plans on this? Or is the DocBook TC consider 
this out of scope? I couldn't find anything in this regard in the DocBook 
V5.0 Howto. 


Thanks,
Tom

-- 
Thomas Schraitle