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

Tag syntax (was Re: Proposal: 'tag' URIs)

From: Tim Kindberg <timothy@hpl.hp.com>
Date: Sat, 28 Apr 2001 09:26:08 -0700
Message-Id: <>
To: "Sean B. Palmer" <sean@mysterylights.com>
Cc: <uri@w3.org>

As Sandro has thanked Michael (which I second), I'd also like to thank you 
for your thoughtful comments.

Now we can go back to diagreeing....:)

At 03:01 AM 4/28/01 +0100, Sean B. Palmer wrote:
>The function of "//" according to RFC 2396 is that anything that
>follows it is an authority component [1], up to the next "/" or "?".
>That it can be used for relative links within the same scheme is
>irrelevant to the semantics of the URI itself. A domain name/email
>address and a date is clearly an authority component, so why not use
>the proper syntactic identifier for it as set out in the URI RFC?

We _really_ don't want tag URIs to be taken for URLs. Compare:


That's too close to comfort for me, and it wouldn't get much better if I 
put in a more reasonable port number than '9'. So I have to ask: does RFC 
2396 mandate the use of the '//' and '/' ? It doesn't seem to me that it does:

"a subset of URI do share a common syntax for
    representing hierarchical relationships within the namespace.  This
    "generic URI" syntax consists of a sequence of four main components:


The 'authority' part of such a URI is supposed to be a server (emphatically 
not so in our case) or a 'registry' -- and we're never told what semantics 
that is supposed to have. Is 'champignon.net;1' a 'registry' under some 
reasonable interpretation? No -- a registry is where you store stuff, and 
nothing is stored at champignon.net;1 (except, conceptually, a list of all 
tags minted so far -- so the assignees don't accidentally 're-mint' a tag).

Formally, tags seem to me to have more in common with URNs than with those 
'generic URIs': they're designed to be of the form 
tag:nameSpace:specificID, where nameSpace happens to be constructed from an 
existing notion of an authority.

So I'm for tag:champignon.net;1:tims-thing.


Tim Kindberg

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Received on Saturday, 28 April 2001 12:11:39 UTC

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