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AW: Section 3.5. Passing fragment identifiers to other systems.

From: Svensson, Lars <svensson@dbf.ddb.de>
Date: Mon, 1 Mar 2004 13:44:15 +0100
Message-ID: <0DD42F8743AED41197470020480E35CF02E8A6C4@DBF-EX1>
To: uri@w3.org

In litteris suis de Freitag, 27. Februar 2004 17:25, Martin Duerst
<mailto:duerst@w3.org> scripsit:

> At 11:39 04/02/25 +0000, Hammond, Tony (ELSLON) wrote:
>> It would seem that the historical use of fragment components has been
>> to provide an addressing mechanism into a resource representation
>> following a retrieval operation, as commonly used in HTTP requests.
>> But in a pure information context there may well be
>> non-dereferenceable URIs such as INFO which still have a clear need
>> to articulate secondary resources with respect to primary resources.
>> So I do query what the role of media type is in these contexts.
> I think if these are really totally undereferencable, then only using
> slashes is much better. If they are to be dereferencable via various
> indirection mechanisms, then the fragment identifier gets carried
> over to the result of subsequent retrieval.   
To me, only using slashes implies different semantics as opposed to
fragment-ids. Consider a library classification translated into several
languages. Representing this as an info:-URI could lead to (using the bogus
WorldWideWebClassification) info:wwwc/somenotation. Sometimes, however, it
makes sense to indicate the language of the classification schedule used,
e.g. if some particular translation goes deeper into detail. If, for
instance, the Vatican translated the wwwc into Latin and decided to add
classification entries for St. Peter's and the Sixtinian Chapel (situated
beneath the Vatican), they would put together 'qwer' for the Vatican, 't'
for St. Peter's and 'y' for the Sixtinian Chapel ending up with the notation
'qwerty', or info:wwwc/qwerty. Since this is a non-standard notation
existing (so far) only in the Latin translation, a librarian wishing to
verify ist use must know where to find it. The aspect 'language' is in this
case secondary to the notation itself, so the use of a fragment identifier
makes sense, thus info:wwwc/qwerty#la would be the way to go. As work goes
on and this notation is adopted by other translations, we could have
info:wwwc/qwerty#se, info:wwwc/qwerty#tw, or info:wwwc/qwerty#de, all three
being sub-aspects of the *actual* notation info:wwwc/qwerty.
Martin's suggestion to use slashes instead would produce
info:wwwc/qwerty/la, or info:wwwc/qwerty/se which (at least to me) has
different semantics. Here, the language component is not a different aspect
of the *same resource* but instead one step further down in the hierarchy
denoting a *different resource*. Or am I wrong?

Graham Klyne [gk@ninebynine.org] wrote:

> In such an environment, I'm not sure that it is at all meaningful to
> employ a fragment identifier at all.  (Reminds me of: "Doctor, it
> hurts when I do <this>".  "Then don't do <this>".)
I'd say it depends on what and how necessary <this> is. If it's "hit my toe
with a large hammer", the doctor is right. If it's "breath" or "walk", I'm
not so sure...



Dr. Lars G. Svensson
Die Deutsche Bibliothek
Informationstechnik / Projekt DDC-Deutsch
Tel.: 069 / 1525 - 1752
Received on Monday, 1 March 2004 07:45:40 UTC

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