RE: A schema that uses attribute values to enforce content structure rules?

> I am trying to express the semantics of our content model in 
> an XML schema. I have a type whose allowed content is 
> function of the values of an attribute. 

That's a classical example of what you can do with "conditional type
assignment" in XML Schema 1.1. It's available in Saxon 9.1 if you want to
try it out. It can't be done in XSD 1.0.

Michael Kay
http://www.saxonica.com/