Re: HTML Link Type Model

Craig Hubley (
Fri, 19 May 95 04:15:10 EDT

> But by abandoning REL/REV, you lose the expressive power
> provided by describing the relationship in both directions.

Not quite. The fact that some relationships/roles are invertible
can be adequately expressed in other ways. You simply move the
statement that ROLE="indexes" is the inverse of ROLE="is_indexed_by",
somewhere else.

> Or we could abandon the use of verbs along with the "WWW link model"
> and just stick with nouns. Would that work for you?

As I mentioned earlier, many of the useful words (like "index") are
both. We can't abandon the "WWW link model" without IMPOSING A NEW
ONE on the WWW. As I have stated now several times, HTML can only
define an *interface* to the rest of the WWW, as not all documents
on the WWW are in HTML. This interface had better be consistent
with the "WWW link model", even if we end up having to rewrite the
"WWW link model" to do so. I propose that that's what we have to
do. At least, I think I will move my efforts in that direction,
and (for HTML) concentrate on link types that can safely default to
'goto (HREF)', which is the only implemented part of the "WWW link
model". That is, we *know* that WWW documents will know how to do
this (although for some, like RTF, it is not exactly clear how yet).

There *is* an "implemented WWW link model", and it is 'goto (HREF)'.
A means of supporting functions other than 'goto' has not yet been
defined. Therefore it is dangerous to specify behavior that cannot
safely default to 'goto (HREF)' or require that browsers understand
it. The basic links types SCO has implemented affect presentation
not navigation, and so their effects can be confined to HTML. But
anything that might, for instance, present one page as two, with
two different URLs (such as "INCLUDE") has WWW-wide implications.

Craig Hubley                Business that runs on knowledge
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