I still haven't had a chance to fully review the schema (and in fact I'm
still trying to get my head around what a schema is and how to read it
properly), but I did notice a few things:

Did we decide to get rid of the USE attribute under file?  I still haven't
been fully reunited with my files since the move, so I'm having to rely on
memory here and I don't really remember.

Use of case in attributes: Are XML schemas specific about use of case as
DTDs are?  I know (or I hope) that no one is ever going to have to get
their hands dirty and actually mark up examples, but if they ever did, the
mixing of upper and lower case in the names of attributes is bothersome
(MIMETYPE versus href).  A picky comment, but...

Should the value of the extent attribute on areaType be "long" rather than
"string" since exttype will qualify what will (I assume) be a number?

Okay, that's all for now.  Back to the XML Schema Primer...