Please investigate the pointer I gave in my earlier message:
http://www.hal.com/~connolly/html-spec
You'll find links to the spec in hypertext, the DTD, "Reference card"
views of the DTD, mail archives for rationale, and just about
everything I know about HTML.
In particular, check out the validation service and Earl Hood's
dtd2html view of the DTD.
I could post URLs to all of the above, but I'd like to encourage folks
to poke around a little by themselves.
If you can't find something, let me know.
Dan