Re: DTDless instances

Mike S-McQ wrote:

> I think there are several reasons to expect DTDs might be unavailable
> for some documents:

Thanks for the list. I'm glad to see that someone else is
considering the scenario:

>     write a DTD, it would be the DTD that was required to conform to the
>     document, not vice versa; 


> I don't
> expect them to be rare, and the scenarios I outline are intended to
> persuade you that the idea is not in itself reprehensible.

I didn't ever think the idea was reprehensible: on the contrary I'm
much in favor of it, and going on current user perceptions of
Web/HTML/SGML/XML, I do expect the vast majority of documents to be
DTDless for a very long time.

> glancing at the DTD.  Another is that fetching the DTD -- particularly
> if it's in five or ten or twenty files, involves a network performance
> hit that most information providers would like to avoid.  (I did fetch a
> TEI-encoded document from Peter's project once; fetching the TEI DTD
> across from Ireland occupied the machine for ten minutes.  Particularly
> ironic, of course, given that the entire thing was already available
> locally, including Peter's local modification files ...)

This is why it is crucial IMHO that XML (and other SGML) browsers come
with complete copies of all the popular DTDs and character entity
files. Obviously we can't force browser authors to do this, but my
guess is that most authors will prefer to use an existing DTD -- if
they use one at all -- rather than design their own, and it could
reduce bandwidth hugely if local copies were used. There would need to
be some kind of updating mechanismn, but that's a job for another day.