Re: Revision information for HTML documents

Ian S. Graham (
Mon, 18 Dec 95 11:47:13 EST

Dan Connolly wrote:
> In message <9512181558.AA14083@sso-austin>, Ben Combee write
> s:
> >
> >Rather than extend HTML again (I'm a bit of a minimalist here),
> Yeah verily! Fight the good fight, my man!
> > why not
> >expand the valid content types for WWW browsers/tools to include something
> >like application/x-rcs. Reasons for this:
> >
> >* The file format exists and is well documented.
> >* A large code base exists for handling these files.
> >* RCS, being outside of SGML, can handle changes without funny DTD tricks.
> >* This easily handles lots of levels of changes, not just the one level
> > that a simple <INS>/<DEL> or CLASS="added"/"deleted" would have
> >* A browser that could graphically show RCS changes would be a killer app
> > for revision control enthusiasts.
> I'm sold. Anybody with time to hack this up? You could probably score
> big in one of the Java applet contests. (Is there a python applet
> contest? Safe-Tcl?)
> Dan

I like this example also, but -- having initiated this whole INS/DEL
discussion, would like to point out that computer code is not the
only place this INS/DEL is relevant -- in fact,
code is probably the least important, in the long run. My particular
interest was for legal or other text documents, where the reader needs
to see the insertions and deletions marked appropriately (struck out,
highlighted, etc) so I *need* information about the differences present
in some way in the document itself. I also want these differences
available to visually impaired users (text-to-speech, braille, etc),
and eventually to authors using other languages. These requirements
really call out for some sort of ins/del semantic markup in the
(HTML or other language) document.

There is a fine line between adding HTML/SGML functionality and moving
that functionality over to applets. Applets are great, but they also make
it easy to lose the platform-independence that is one of the strengths
of HTML/SGML. Can I run this applet on a braille, or text-to-speech
browser. No. Of course, I can create special applets for these
environments, but then have to figure some complicated mechanism for
selecting the applet based on the browser, etc etc.

Being an 'HTML minimalist' is fine -- I like to think I am one also --
but the whole point of a markup system is to be able to mark up document
content issues. What is the point of 'minimizing' a document to the point
where every document content-processing issue has to be implemented by
a separate encoding scheme (x-rcs, x-sccs, x-sgml-author-editor,.....),
a new separate applet.

I'd rather first determine, by analysis of some general document editing
issues, whether or not ins/del/move/???? is a markup issue. If it is, then
we can design the minimal number of elements required to do so, and *then*
design applets that take advantage of this semantic content.


Ian Graham ......................................
Information Commons                               Tel: 416-978-4548
University of Toronto                             Fax: 416-978-6110