DOCBOOK: Circumventing restrictions in the WP9 DTD-compiler ?

[Joachim von Jena <jvjena@cs.tu-berlin.de>]

As I mentioned in another message the WP9 dtd-compiler reacts with an error
when compilin docbkx4.0beta2 and refers to the notations part in dbnotnx.mod 

If I delete all NOTATION entries following line 58 in dbnotx.mod,
I can compile docbookx.dtd.

The WP9 XML manual says that NOTATION is one of several catalog entry types
which WP9 currently doesn't use but which are valid (?).

Questions:

- what information is missing if the NOTATIONs are removed in dbnotnx.mod.
  Can docbook be used in a restricted way?

- are the NOTATIONs MIME types?

- can the NOTATIONs information made available in docbook in a different way?

Joachim v.J.