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Re: New feature tag registration drafts available

From: Graham Klyne <GK@acm.org>
Date: Fri, 11 Jul 1997 12:24:56 +0100
Message-Id: <3.0.32.19970710224127.0090ee40@POP.Dial.Pipex.Com>
To: Koen Holtman <koen@win.tue.nl>
Cc: http-wg@cuckoo.hpl.hp.com
At 11:05 PM 7/10/97 +0200, Koen Holtman wrote:

[...]
>To make rapid progress on getting at least the namespace in place, I
>limited the drafts to the namespace only.

Fine.  (And I like the hierarchical namespace approach.)

>> * Section 2.1:
>> 
>>I like your characterization of the problem as a multidimensional search
>>process.  But, following a discussion I had the other day, I wonder if this
>>may be insufficient.
>
>Yes, you often have negotiation in which dimensions are
>interdependent, and the drafts do not exclude such cases (at least I
>did not mean them to).

OK.  (I think it's the term 'dimension' -- it tends to imply a scalar
associated value.)

>I like to think of the namespace as unstructured: there is no
>predefined order in which negotiation on features has to be done.

Another draft to cover a generic negotiation framework?  (Not to specify an
order, but partly to make it clear that there is no predefined order.)

>Another thing which would be outside of the scope of the registry is
>the distinction between the two cases `if the other party does not
>understand the meaning of this tag, it is safe to proceed with
>negotiation' and `if the other party does not understand the meaning
>of this tag, it is *unsafe* to proceed with negotiation'.  Again, I
>think that there are tags for which either one could be true depending
>on the specific negotiation case.  So this distinction would have to
>be conveyed with metadata, which is attached to the tag when it is
>transmitted, rather than being encoded in its registration entry.  The
>metadata format could either be general or bound to a specific
>negotiation mechanism.

Hmmm... I'm not sure one could construct a sufficiently general metadata
fraework either.  I had assumed that such detail would be bound up in the
semantics of a particular tag:  e.g. any component which new about a tag
would know what kind of response (if any) would be needed to conclude
negotiation w.r.t. that tag.

>I plan to make such in/out of scope distinctions more explicit in a
>revision of the scenario draft.

I think it was fairly clear that details of values associated with the tags
were not part of the feature tag.  But I felt there were implicit
assumptions about the range and complexity of values which might be allowed.

>[...]
>>* Section 4.2:
>> 
>>(a) I note that you are still adopting a very web-centric view in
>>notionally application-independent draft.
>
>I intended 4.2 be read as an example, not as an exhaustive list.  I
>see I did not make that very clear in the title, though.

That comment of mine was slightly tongue-in-cheek.  And I just wanted to
raise a flag concerning the possibility of Web-centric thinking allowing
assumptions to creep in.

It was clear from what you wrote that it was just an example.  

GK.
---

------------
Graham Klyne
GK@ACM.ORG
Received on Friday, 11 July 1997 04:28:59 EDT

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