[plug] XML DTD

[Colin Muller]

> I was looking at schemas and they seem (at least at the glance I had) 
> more complex than DTD's. I think schemas, however, have the option of
> being more scalable and extendable.
> 
> There's a few perl scripts floating around the net that can convert
> DTD's to schemas.

Schemas can express any content model which DTDs can, and offer things
which DTDs don't, but you'll still need DTDs if you want to use
entities.

If you want more expressive and constraint possibilities than DTDs
give, Relax NG is favoured over W3 Schemas by many XML gurus (and is
much easier to learn than W3 Schemas):
http://www.oasis-open.org/committees/relax-ng/
http://www.oasis-open.org/committees/relax-ng/tutorial-20011203.html
(The Oasis site seems to be down right this minute).

Colin