On Mon, 1 Nov 2004 14:46:10 -0500
Liam Quin <liam@w...> wrote:
> On Mon, Nov 01, 2004 at 11:36:51AM -0800, Ronald Bourret wrote:
> [...]
> > Not sure why people chose DTDs instead of XML Schemas, but I suspect 
> > it's either because they were coming from the SGML world or because
> > they 
> > started work before XML Schemas were a recommendation.
> 
> Or because they are easier to understand, or because there is wider
> support for them, or because they are more interoperable, or because
> books and tutorials on XML usually talk in detail about DTDS, which
> are, after all, part of the XML Specification, and often omit
> W3C XML Schemas altogether or give only an overview, as they are
> too complex to cover in a small (say, under 1,200-page) book in
> good detail, and in any case the writer may need to devote equal
> coverage to RelaxNG and Schematron.  Wow, was that a sentence?

Candidate for inclusion for W3C XML Schema next version?

Nah, too clear, too unambiguous.

Add: because they are defining documents and have no need for XML Schema's
strong [mis]typing, because they are reluctant to move to RNG yet or at
all (because it lacks W3C imprimatur, usually), or because they need only
some bits of the functionality provided by WXS and are unwilling to accept
the rest of the burden imposed with its use?

> W3C XML Schema support has been growing over the past couple of
> years, and interoperability seems to me to have been increasing,
> but I'd still suggest that people use a DTD if it satisfies
> their needs.

Interop seems to remain within a subset, with, as a recent thread pointed
out, even such relatively important things as UPA controversial and
unevenly supported.  Tool support for advanced functionality, such as
substitution groups, is weak (at best).  The verbosity of the format, as
compared to DTDs or RNG (especially presented as RNC) impedes learning,
maintenance, and advanced usage.  Most use (in my experience) is either
from the typed-information folks, or mandated by buyers whose knowledge of
the distinction between DTD and WXS can be summed up in the phrase "W3C
XML Schema is intended to replace DTDs".

Amy!
-- 
Amelia A. Lewis                    amyzing {at} talsever.com
I don't want what's best for you--
    where will I be when you've found it?
        I pray a lot about these bad feelings inside
            but I can't pray my way through or around it.
                -- Emily Saliers