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Re: New draft of URNsAndRegistries-50 candidate finding available

From: Dan Connolly <connolly@w3.org>
Date: Mon, 12 Jun 2006 17:02:22 -0400
Message-Id: <11ede3b70b92785e1e6572dea2394ac4@w3.org>
Cc: www-tag@w3.org
To: ht@inf.ed.ac.uk (Henry S. Thompson)

On Jun 7, 2006, at 6:42 AM, Henry S. Thompson wrote:
> Hash: SHA1
> For review in advance of the upcoming f2f, if possible:
>   http://www.w3.org/2001/tag/doc/URNsAndRegistries-50.html
> v 1.20 2006/06/07 10:39:55

I have a number of organizational/editorial concerns, but I think just 
one technical disagreement:

The namespace specification, roughly speaking, says that a namespace 
name cannot be assumed to be dereferenceable. Any software component 
that is written assuming that any namespace name must be dereferencable 
is violating the namespace specification. It may be that the namespace 
owner has guaranteed that they will provide a document at the namespace 
name, but this must be on a subset of the entire set of namespace 
names. As a result of this, generic XML software should not be written 
to assume dereferencability of namespace names.

The conclusion should be something like "generic XML software must be 
written to be robust in the case of failure of a namespace name to 
resolve, just like any other URI handling software." It's not a 
violation of the namespace spec to assume that namespace names are 

Editorially, I can see a tension between writing for two different 
  1. an audience that is predisposed to believe what we write, and just 
wants to know what our position is. For this audience, having the 
conclusions up front and the justification later, in case they're 
really curious, seems OK. I think this is the way the document is 
  2. an audience that we're trying to convince. For this audience, 
getting to "fact: URIs support persistence as well as it is in-practice 
possible to do so" before any justification is a turn-off.

Also, there's a 3rd sense of 'persistence' that often comes up in URN 
discussions: persistence of the binding between an identifier and its 
meaning, regardless of availability or otherwise of representations.
I think that http is clearly the most successful technology for this 
sort of persistence too -- [evidently DO has made this case later in 
the doc.]

-- ah.. time to send this... more in the meeting, I suppose.

-- in the meeting:

In DO's case study, the id: case is not hypothetical; ironically, it's 
called tag:

Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 12 June 2006 21:02:35 UTC

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