DOCBOOK: FAQ: XML solution for conditonal sections

[Bernd Kreimeier <bk@oddworld.com>]

Question:
Is there a canonical way to implement an equivalent to SGML marked
sections in DocBook XML. I have prowled list archives a bit, and
followed up on past proposals like XCond. My assumption right now is
that this is best done by introducing a common attribute, and then
attempting to modify the XSLT process to omit all content contained
in an element without the desired attributes? If this is an FAQ and 
there are examples for the taking, I appreciate pointers.

Thanks,
                              b.




Background: 
I have set up a DocBOOK SGML based proof of concept here, but want 
to switch to XML to be able to use off-the-shelf editing tools for 
the Win2K WYSWYG community here. One of the big selling points to go 
for a descriptive markup solution was the ability to have conditional 
content interleaved at a level that is not practical to be implemented 
using external entities and a plethora of small files. The SGML 
implementation relies on marked sections. I have used this before 
with good results (see http://www.openal.org/snapshots/, 
http://www.openal.org/info/).




Some more comments:
A preprocessor solution as frequently suggested does not seem to work,
as introducing a non-XML element in XML source will break XML-aware
editing tools.

While SGML INCLUDE/IGNORE entities aren't the most flexible or elegant
solution, they do the job in a straightforward way.

The DocBook guide seems to lack a "Adding an attribute" example?