> While we've been pondering some basic questions, several folks out there have 
> already built some sample XSchema structures that are worth taking a look at.  
> So far I've seen two and heard of two more.  One of them, from John Cowan, has 
> already been announced to the list, and is available at 
> http://www.ccil.org/~cowan/XSchema-draft-19980601.txt . The author of the 
> other one I've seen is in the process of posting it.
And here it is, along with a list of comments/questions and a list of 
differences from John's proposal:
http://www.informatik.tu-darmstadt.de/DVS1/staff/bourret/xschema.html
Because John posted his first, I had the advantage of comparing the two and 
tweaking mine a bit (thanks, John ;).  Both proposals are substantially similar 
to each other, as well as to the XML-specific parts of XML-Data.  They differ 
mostly in element names and in how ?/+/* and attribute types are represented.
All of which leads me to wonder if is there an (as yet undiscovered) way to 
represent XML content models in XML without using the basic structure:
<XSchema>
   <ElementDef>
      <ChoiceOrSeq>
         <ElementRef>...</ElementRef>
         <ElementRef>...</ElementRef>
         ...
      </ChoiceOrSeq>
      <Attrs>
         <AttrDef>...</AttrDef>
         <AttrDef>...</AttrDef>
         ...
      </Attrs>
      <OtherStuff>
         ...
      </OtherStuff>
   </ElementDef>
   ...
</XSchema>
-- Ron Bourret