namespaces discussion

Richard L. Goerwitz richard at
Thu Sep 10 21:40:48 BST 1998

Tim Bray wrote:

> >> [W]hy can't...elements themselves [have] a namespace URI which addresses
> >> a DTD entity for that particular element?

> This will never happen.  The namespace URI is just a name.  It would
> be really wrong to assume you can go there and get a DTD
>  1. some namespaces (like HTML, MathML, a few others) are going to be
>     very widely used, and it would be silly to force one poor server
>     somewhere to guarantee a DTD-on-demand for them

Some DTDs will be widely used whether or not one uses them for name-
spaces.  (Deadpan look follows.)

As for namespace URIs being just names:  We're in this deep.  Why not
associate namespaces optionally with DTDs (not necessarily via the name-
space URI)?

>  2. some namespaces aren't going to have DTDs or any other kind of schema

Then they won't validate.  That's all.  Or (lacking an associated DTD),
they could be validated in the kludgy fashion that the current namespace
spec seems to require (i.e., you have to make your DTD aware of all the
new:elements your use of namespaces requires - with allowances for de-
faulting :-( ).

>  3. some schemas aren't going to be DTDs

That's another issue that we will just have to see played out.  To me
it looks as if the people who insist on strict SGML conformance are, in
fact, the ones who are driving the wild proliferation of extensions 
before XML has barely made it out of the gate.

In an ironic twist of fate, they may be the ones most responsible for
DTD and such quickly becoming legacy features.

This may not be a bad thing.  Either way, though, the effort spent on
SGML conformance is starting to look noble but in vain.


Richard Goerwitz
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