XHTML MOD model module

At the moment XHTML MOD requires users to construct a model module
specific to the combination of modules they are using.

XML (like SGML) has a feature that was designed just for this situation:
it says that it is NOT an error for a content model to mention an
undefined element (http://www.w3.org/TR/REC-xml#elemdecls); it only
becomes an error if such an element occurs in an instance.

Thus if you create a model module that works when you include all
modules, that same model module will also work just fine if you include
only a subset of the modules. (This won't of course handle the
distinction that transitional allows inline content in some places where
strict doesn't.)

I would suggest that such a model module be included with XHTML MOD.

James