Re: HyTime HTML 3.0 proposal

Daniel Glazman (
Thu, 16 Mar 1995 09:58:58 +0000

In message <9503160916.AA09831@cln46ib.sid.> 16 Mar 95 03:16:44, wrote:

> Yes this will cause a *small* problem of backward compatibility.
> Is the problem of backward compatibility so important? I don't see any
> reasons why a W3 browser or any other tool could not support several different
> DTDs.

This can be linked to Ed Levinson last draft about SGML transport in MIME

There are so many different possibilities to solve this problem

* DTD carried in the instance itself
* HTTP answer carrying a multipart/sgml (or an ersatz of it)
containing instance, DTD, DSSL sheet, ...
* PUBLIC identifiers

As Christophe points it out, SGML parsers are available on the market and
they can be integrated in HTML browsers/editors. Oh, sorry, in the former
sentence, please read "must" instead of "can" ;-)

Even YASP can be used as a non-provided dynamic library in a commercial
product if copyright problems really scare you...

> What HTML 3.0 proposes is to add more powerful constructs to do tables, maths and
> so forth. Who said it would take twice as much work to create a hyperlink ? It
> all depends on the tool you use to produce your document. Of course if you use
> emacs or vi you'll have to type in more tagged information. But with editors like
> HoTMetaL or other WYSIWYG editors all thos mechanisms could be hidden from the
> user. Just make a link with a point and click interface. Of course the new
> NMLOC and NMLIST elements would be invisible both in browsers and WYSIWYG editors.

This is of obviously the main goal of a good DTD: be able to provide a so
logical document design that 1) editors can hide tags 2) writers do not
need to know HTML at all. Such 100% Wysiwyg click-and-create editors are
currently "in the pipe" and I don't think that we should see HTML as a
Emacs-edited format any more.
I wrote "logical"; logical does not mean simple.

> Declaring the entities in the document type declaration could also be an optimization
> advantage for browsers. Once the DOCTYPE declaration is parsed they know all
> the entities that are going to be used in the document instance and therefore
> they can get them in advance.

It can also be an advantage for editors... You all know the "Local & Active"
character entities in HotMe*al. A general entities' management could be
very easily implemented/handled with such a mechanism.

Regards from a cold-cold Paris today (Zeus, how freezing it was on my Vespa
this morning !-()


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