Refer to keys in the other grammar.

Say I have a "XHTML.rng", which defines XHTML schema. There is the ID
attribute in XHTML, so XHTML.rng somehow declares those attributes as
IDs.

Now, I have "mine.rng", which defines my schema. My schema uses XHTML to
provide documentation. Can I refer to IDs in XHTML from the other part
of "mine.rng"?

It seems to me that none of the current design allows me to do this.


Is it possible to extend the current design to incorporate this feature?
Or should it be forgotten?


--
Kohsuke KAWAGUCHI                          +1 650 786 0721
Sun Microsystems