[XML-SIG] Looking for namespace examples...

[Stuart Hungerford]

Two messages in one day!  It must be a full moon
or something.

This one is a bit more prosaic: I'm looking for some
realistic examples of DTD's and XML documents that
make use of namespaces.

My understanding is that a validating parser will not 
treat namespace prefixes as "special" in any way in 
a DTD. I've seen short examples where the xmlns:foo 
attribute is defined as a FIXED attribute (in David
Megginson's "19 questions" document), and now
I'm a bit confused.

Can anyone point me to some good learning
examples?

Thanks,

Stu