RE: declaring xml:id attributes

> If I want to restrict the 
> type of the xml:id attributes of one kind of element in one 
> way and the type of the xml:id attribute of another kind of 
> element in a different way then I seem to have a problem 
> since with the approach you described you cannot declare 
> different variants of xml:id attributes for different kinds 
> of elements.

In XMLSchema, if an attribute is in a namespace, and it's a different
namespace from its parent element, then the attribute declaration must be a
global declaration, which means it can't vary from one element to another.

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