W3C home > Mailing lists > Public > uri@w3.org > September 2001

RE: Using fragment identifiers with URNs

From: Al Gilman <asgilman@iamdigex.net>
Date: Thu, 27 Sep 2001 12:24:25 -0400
Message-Id: <Version.32.20010927083446.03fe2f00@pop.iamdigex.net>
Message-Id: <Version.32.20010927083446.03fe2f00@pop.iamdigex.net>
To: Stephen Cranefield <SCranefield@infoscience.otago.ac.nz>, "'uri@w3.org'" <uri@w3.org>
Better quote.

[quote]

   The semantics of a fragment identifier is a property of the data
   resulting from a retrieval action, regardless of the type of URI used
   in the reference.  Therefore, the format and interpretation of
   fragment identifiers is dependent on the media type [RFC2046] of the
   retrieval result.  [snip]

[end quote]

I would recommend that you read this as substantiating Roy's claim that the
document asserts scheme independence for what it says about #fragment
interpretation.  And URN vs. URL independence.

The upshot of looking at generic URN religion likewise should be that "URNs on
the whole don't tell you about the means of retrieval" principle should
also be
interpreted as "URNs on the whole don't tell you about the feasibility of
retrieval" as well.  'Resources' are by common usage expected to be of some
use.  The generic 'retrieval' notion is just whatever you have to do in order
to be ready to use the Resource.  This is not required to be universal, but it
is just so endemic to the many ways of providing value added that it is
assumed
by default.

A URN scheme that denies all possibility of retrieval is not impossible by the
URI generic rules, it is just bad market positioning of technology, a "market
loser in waiting."

Don't look for a more computer-understandable prior notion than the above
description that 'resource' is something of potential utility; and a URI as a
string which assists authors in recording a reference to a resource and
consumers of the recorded reference in isolating the indicated resource.  The
only thing that _all_ URIs share is some rules about how you put characters in
the string.  This discipline allows strings written in a distributed
fashion to
avoid accidental string-compare collisions.  End of URI-universal story.

The specification of the uniform syntax for the unified scheme of reference is
borne out our hard-won small agreements on what we would all _do_ from people
with very different _notions_ of what resource identifiers _should be_.

How you interpret what it means depends on the characters in the string, and
quite legitimately may depend on the context in which you are interpreting
them.  At least you won't interpret a reference as referring to the wrong
resource.

Al
Received on Thursday, 27 September 2001 12:19:40 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:25:03 UTC