Re: SGML and XML

Mr. McQueen writes

>The only remaining types of information for which a DTD is essential are:
>  - content models (for validation)

Not necessary for a parser per se. The parser can do it's job without 
validating it, and validation of content models could be performed
using the post-parse data structures (event stream/tree).

>  - attribute types and default values (for recognition of IDREFs
>    etc. and for full provision of all attributes which apply to each
>    element instance)

Yes. I would be interested in hearing why people wish to necessarily
have the entire attribute set appear on each element instead of just
the attributes that had values specified (ie. I wonder if applications
couldn't be built for the latter case that are effectively the same as
the former).

>  - entity declarations (for resolution of entity references)

Only really needed for the *type* of the entity, which, assuming
object labelling in storage managers, may be available elsewhere.

Resolution can begin with the name of the entity itself...

>  - element vs. mixed content (for elimination of white space in
>    element content)

This is not a strictly *necessary* distinction.