Re: REL and REV standard?

Murray Maloney (murray@sco.COM)
Wed, 16 Nov 94 11:48:47 EST

> Tim Berners-Lee writes:
> > From: Paul Burchard <>
> > To: Multiple recipients of list <>
> > It should be mentioned that, despite the lack of an "official" set of
> > relationship values, there's long been a list of suggested values at
> >
> I have tried to keep that up to date with all suggestions which
> I have come across (since 1990). An interesting thing is that
> the list never seems to blow up and most suggestions for additions
> are for things already in it.
> This list is refered to both by HTTP WWW-Link: fields and
> HTML REL and REV. I feel that it should be a separate spec, as it
> is largely orthogonal to the others. But I'm open to be persuaded.
> Maybe a snapshot of the list could be included for information as
> a non-binding appendix to the HTML spec.
> Tim
Thanks Tim,

I think that even if the basic list of keywords were provided
-- establishing current practice in 1994 -- then I would be
more inclined to accept a pointer to an informative appendix
or to a WWW site. However, I may add that URLs are fragile
and I would certainly prefer to see an informative appendix.

As to the specific values which are documented at the CERN URL:

I have to say that I am a bit confused by the relationships
as described and I would certainly benefit from more detailed
descriptions, with concrete examples and descriptions of how
a sample application might deal with a <LINK> or <A> tag
with REL and/or REV attributes set with these keywords.

I also note that that there seem to be very few relationship
keywords that can be used to describe hierarchical relationships
(Precedes, Subdocument, and possibly Embed and Present),
and also very few that can be used to describe a relationship
to common parts of document structures (Table of Contents, Copyrights, etc.)


Dan, I think, posted a list a few days ago that included many
keywords that are not present of the list that Tim maintains.

Keywords that are currently being used in the SCO help browser

Previous - points to previous node in linear document
Next - points to next node in linear document
Contents - points to a table of contents related to this node
Index - points to a standard index related to this node
Navigate - points to a navigation node related to this node

Others that we'd like to use in the future include:

Library - pointer to aggregation of document sets
Set - pointer to aggregation of documents
Document - pointer to top-level ancestor in document heirarchy
Chapter - pointer to chapter-level node
Section - pointer to section-level node
Parent - pointer to parent in document heirarchy
Sibling - pointers to siblings in document heirarchy
Child - pointer to children in document heirarchy

I'm looking for a very well-defined and specific set of relationships.
These are some that come off the top of my head, but I am sure
that I will think of others. Our experience in developing a help sstem
with an adapted version of Mosaic has shown us that the power of
WWW-capable browsers is increased significantly through the use
of the REL and REV attributes.

Please, let's broaden this discussion.
I think that we could have a lot to gain.