Re: Best Practices for Establishing Namespace Name

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C. M. Sperberg-McQueen writes:

> The meaning of some identifiers is given in a way that
> guarantees permanence of the meaning assigned.

I'm very interested in examples of this for identifiers useable on the
web, particularly ones which participate in what's been informally
called the 'follow your nose' property, or, per [1], "grounded in the
Web":

  the specifications required for their interpretation should be
  discoverable by recursively following links starting with the
  specification for URIs [rfc 3986].


> If URLs mean things by virtue of the actions and/or intentions of
> their owners (which is what I understand the TAG's story to be),
> then when the owner changes, the meaning is necessarily subject to
> change.

Indeed.  As I said in my previous message, diligence is required to
forestall this, and it's not unreasonable to expect/mandate diligence
in cases where long-term persistence is a high-level goal.

> The difference at issue is not whether, when you dereference
> something, you get something 'misleading' or not.  The
> issue is whether the prescribed methods for determinining
> the denotation of an identifier guarantee stability of
> denotation over time or not.

> On the account offered in your email, the system of using
> URLs as long-lived identifiers seems to depend on (a) the
> proposition that a URL has a given meaning just when the
> owner of the relevant domain assigns it that meaning, and
> (b) the proposition that a URL has a given meaning
> whenever we feel like interpreting that way, regardless
> of the actions of the owner of the relevant domain.
>
> The TAG may have no trouble reconciling those two
> propositions; I confess that to me, they just look like
> a contradiction at the heart of the TAG's edifice.

Insofar as the TAG is in a position to prescribe anything in this
area, (1) is indeed the official story (actually, it's RFC 3986 which
_prescribes_ in this case).  Your (2) is a lot stronger than what I
said, which was in any case _not_ a TAG position, or even anyone's
proposal of a _possible_ position, but rather an empirical _claim_,
with respect to a small number of very widely deployed namespace URIs.
_If_ that claim is true, that means that the world is not behaving as
has been 'prescribed'.

There is in fact a lively debate underway about a variety of possible
accounts of URIs and how they identify things, which may or may not
succeed in reconciling theory and practice in a useful way.

The relevance of all this to the issue at hand is, I think, not very
great.  As long as the purpose of creating namespace URIs at all
involves 

 a) at least the possibility of value-add from web-access via the
    namespace URI;

 b) a commitment to diligence wrt any registrations which underlie
    whatever web-access mechanisms are in prospect.

then my advice stands -- http: URIs have a clear advantage over any
other form of URI.

ht

[1] http://www.w3.org/2001/tag/doc/selfDescribingDocuments.html
- -- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
                         Half-time member of W3C Team
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged spam]
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Received on Wednesday, 2 September 2009 18:26:01 UTC