Joe Kesselman <keshlam-nospam@c...> scripsit:

> In other words:

In future, please quote or paraphrase the message that you are commenting 
on.

>As always, a DTD -- or a schema -- is only a partial
> description of what makes a document correct and meaningful.

It depends on. There's no law that requires additional rules, though pure 
syntax as such _is_ somewhat boring.

> Think of
> these as "higher-level syntax checking"; the application is always
> going to impose semantic constraints as well.

What's "higher-level" here? Anyway, in the issue discussed in this thread, 
it is the additional _syntactic_ constraints that imply that a certain kind 
of document is not an HTML document. There's nothing semantic in the 
requirement that a document contain a specific DOCTYPE declaration or that a 
document contain a <title> element. (Requiring that the <title> element 
contain text that is a descriptive name for the document, especially for use 
as a title for it in different contexts, would be a semantic requirement. 
Whether HTML specifications make such a requirement is debatable; the prose 
in the specs is a mixture of normative-looking prose, comments, hints, 
wishful thinking, etc.)

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/