>  QUESTIONS
>
>  1. When defining an XML vocabulary, should behavioral information
>  always be specified?
no.
>
>  2. Does it make sense to define an XML vocabulary without specifying
>  behavioral information?
yes
>  3. Are there two categories of XML vocabularies:
>
>  (a) XML vocabularies with behavioral instructions
>  (b) XML vocabularies without behavioral instructions
>
yes. Although I think vocabularies without behavioral instructions are
vocabularies that would normally be understood as purely data
specifying in nature.

>  As shown above, XSLT, XML Schema, and XHTML are XML vocabularies that
>  fall in the first category.
>
>  Consider a "Book XML vocabulary."  Here's a sample document that
>  illustrates the Book XML vocabulary:
>
>  <?xml version="1.0"?>
>  <Book>
>     <Title>The Wisdom of Crowds</Title>
>     <Author>James Surowiecki</Author>
>     <Date>2005</Date>
>     <ISBN>0-385-72170-6</ISBN>
>     <Publisher>Anchor Books</Publisher>
>  </Book>
>
>  Suppose I write a specification for this XML vocabulary.  For each
>  element I specify its contents and the intended usage.  But suppose
>  that I don't instruct application developers on the (default and/or
>  mandatory) behavior of each element.  How will I certify that the
>  application is compliant?


Because the general purpose of a Book vocabulary in all the examples
I've seen is in the holding of book specific data. There are of course
real world Book specifying vocabularies that are concerned with how a
'book' must behave, the behavior being specific to a particular type
of media.

Cheers,
Bryan Rasmussen