Re: MIME as a hypertext architecture

----- Original Message -----
From: Dan Connolly <connolly@pixel.convex.com>
Date: Sat, 06 Jun 92 00:53:20 CDT
Subject: MIME as a hypertext architecture

> The HTML format is under stress from several issues:
>  * We need an SGML DTD so that we can parse HTML using
>  something besides the public implementation of WWW, and so that
>  we can verify documents converted from other authoring
>  systems such as GNU info, Andew's EZ, or FrameMaker.

Good idea, but are DTD and SGML structures strong enough? You are saying
yourself that HTML isn't SGML at the moment (7 Jun 1992), but does it need
to be? We could make up some new kind of validation system, and make *that*
a subset of SGML.
HTML is quite strong (strong enough?) with just the material that Tim has
published (see http://info.cern.ch/hypertext/WWW/MarkUp/Tags.html).
Don't forget, Tim has already pointed out that there is enough documentation
on the content of HTML (see [1])

> This is a proposed architecture for global hypertext, addressing
> the issues raised by the WWW project, but using the MIME architecture.
It'll never take off. This HTML stuff will be restricted if you send it with
a MIME type. Just make a system that doesn't use MIME, i.e. only uses plain
ASCII. Then we can, say, put an HTML tag <HTML> at the top, and clients will
know it is HTML.

> Then we define a new subtype of the MIME text content type called
> x-HTML. This is an SGML markup language using the default SGML declaration
> (i.e. the reference concrete syntax, default processing limits, etc.)
> and the HTML DTD (included below).
Why don't we call it XHTML instead? How about a MIME type of text/html,
that's if you want to use MIME. I don't believe it'll work, personally...

In the following DTD, I suggest you change:
> <!ELEMENT A - -  (%inline)+>
> <!ATTLIST A
>  NAME CDATA #IMPLIED
>  PART ENTITY #IMPLIED >
to
<!ELEMENT A - -  (%inline)+>
<!ATTLIST A
  HREF CDATA #IMPLIED
 NAME CDATA #IMPLIED
  PART ENTITY #IMPLIED >

I think, assuming you left that out by accident, the removal of the HREF
attribute might have dire consequences...and I strongly suggest you change
it to my fragment post haste. (Note: Does it matter what case we use for all
of this?)

> ---
>
> <!-- This DTD was produced by DeveGram on Tue Jun  2 18:58:16 1992 -->
> <!-- and hand-edited by connolly@convex.com -->
>
> <!--     Parameter Entities       -->
>
> <!--      Terminal symbols        -->
>
> <!ENTITY % words "#PCDATA" >
>
> <!--    Non-ELEMENT symbols       -->
>
> <!ENTITY % inline "%words | A" >
> <!ENTITY % text         "%inline | P" >
> <!ENTITY % heading "H1|H2|H3|H4|H5|H6" >
>
> <!ENTITY lt "<">
> <!ENTITY gt ">">
> <!ENTITY amp "&">
>
> <!ENTITY lt. "<">
> <!ENTITY gt. ">">
> <!ENTITY amp. "&">
>
> <!--     Document structure       -->
>
> <!ELEMENT html O O  (TITLE, NEXTID?, ISINDEX?, section+, ADDRESS?)>
>
> <!ELEMENT TITLE - -  (%inline)+>
> <!ELEMENT ADDRESS - - (%text)+>
>
> <!ELEMENT NEXTID - O EMPTY >
> <!ATTLIST NEXTID N NUMBER #IMPLIED>
>
> <!ELEMENT ISINDEX - O EMPTY >
>
>
> <!ELEMENT section O O ((%heading)?,
>    (
>    %text |
>    section |
>    MENU |
>    UL |
>    OL |
>    DIR |
>    DL)+)>
>
> <!ELEMENT (H1|H2|H3|H4|H5|H6) - -  (%inline) >
>
> <!ELEMENT P - O  EMPTY -- paragraph SEPARATOR -->
>
>
> <!ELEMENT A - -  (%inline)+>
> <!ATTLIST A
>  NAME CDATA #IMPLIED
>  PART ENTITY #IMPLIED >
>
> <!ELEMENT MENU - -  (LI+)>
>
> <!ELEMENT UL - -  (LI+)>
>
> <!ELEMENT OL - -  (LI+)>
>
> <!ELEMENT DIR - -  (LI+)>
>
> <!ELEMENT LI - O  (%text)+>
>
> <!ELEMENT DL - -  ((DT, DD)+)>
>
> <!ELEMENT DT - O  (%inline)+>
>
> <!ELEMENT DD - O  (%text)+>

> Within HTML documents, SGML IDREFs and IDs are used to reference and
define
> elements of a document. (I think HYTIME defines a way to reference
elements
> without explicit IDs.)
Why not. IDs are quite useful.

Find here attached my (late - I should have sent this a few months ago, Dec
'91/Jun '92, but I forgot!) reply to Tim B-L about defining HTML as it
currently is.

[1] My reply to Tim Berners-Lee

Date: Tue, 29 Oct 91 10:03:11 GMT+0100
From: timbl (Tim Berners-Lee)
To: connolly@pixel.convex.com, www-talk
Subject: Re: status. Re: X11 BROWSER for WWW

> > If you could round up some info on exactly what I can expect to see
> > in an HTML file, and some idea of how you want it formatted [I have
> > the HTML doc and the LineMode browser, but if you've got time to
> > give me a little more info...] I'll be ready to tackle that pretty
> > soon.
> You ask for info on exactly what you can expect to find in an HTML
> file, but you've read the two HTML files about HTML.  What is missing
> from there?
> Here is some discussion about the tags -- where it's not in
> http://info.cern.ch/hypertext/WWW/MarkUp/Tags.html I have updated
> that document now.
> Most of the tags are just style tags: this goes for the headings H1
> to H6, the lists UL and OL with list elements LI, the glossary DL
> with elements DT and DD.

Tim: if Dan is going to turn HTML into an SGML subset, then I would advise
you to make it fully structural, rather than referring to such tags as
"style tags". Maybe we could add styling in at a later date. Otherwise, HTML
seems to be pretty well defined. Dan may have problems getting people to
validate it using his new "DTD" though!

Kindest Regards,
Sean B. Palmer
HTML Development - http://xhtml.waptechinfo.com/future/

Received on Saturday, 14 October 2000 08:25:34 UTC