* inheritance and subclassing among XML element types -- I don't think
that this really has much to do with OO at all. I do think that the XML
standard should explicity support these features.
* application-specific conventions for marking up OO patterns in XML
documents. This is what the prototype example seemed to do. I do not
think we need to nor should change the XML standard to support these
types of concepts, but they are interesting examples of XML modelling of
structures from other disciplines.
* patterns for representing XML documents *in memory* *in applications*
(i.e. MVC, constraint-based, aggregation).
Perhaps I am the only one who got confused by the way the thread is
sliding between these without differentiation, but if not, hopefully
I've helped clarify it for someone.
Paul Prescod