XHTML Basic XML Schema

Hey guys,

I'm just playing around with XHTML Basic and want to extend it
by my own elements. Does anybody knows where I can find
a XHTML Basic XML Schema ?

I know that there is a XHTML 1.1 DTD, and there are different
modules - so I can build togehter my DTD for XHTML Basic and 
translate it to a XML Schema - but is there anywhere a final 
XHTML Basic XML Schema.

might you can help me

regards
Oliver Schramm

-- 
GMX - Die Kommunikationsplattform im Internet.
http://www.gmx.net