Suggestions for an UBL ExtensibleContent area

Hi,

I updated some parts of the earlier document on our discussion point on a
possible ExtensibleContent area for Wednesday, it was decided not to do a lot
of additions to the document because the additions I was working on after a
bit seemed to cloud the issue; these were such things as example extensions,
possible varying validation mechanisms (Schematron, Namespace Routing
Language http://www.thaiopensource.com/relaxng/nrl.html ), and application
usage (transformation). This is more the kind of thing that should be moved
to HISC if ExtensibleContent was accepted. 

Thus the only changes to the document are trivial ones. Sorry about the time
it took but after it was decided to forego some of the additions I had to
edit them back out, and on top of that I've been having a very strenuous two
weeks here in various projects. 

Cheers,
Bryan Rasmussen