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[VM] cookbook issue in naming 'hash namespaces'

From: Ralph R. Swick <swick@w3.org>
Date: Tue, 14 Feb 2006 11:58:23 -0500
Message-Id: <5.1.0.14.2.20060214111205.03737fb8@127.0.0.1>
To: Alistair <a.j.miles@rl.ac.uk>
Cc: public-swbp-wg@w3.org

Alistair,

I just noticed an issue in the way the current cookbook editor's draft
refers to hash namespace URIs.  Sorry for not explicitly raising this
earlier, as I suspect that it may represent something fundamental
in your view of vocabulary naming.

In recipes 1, 3, 1a, and 3a the current editor's draft [1], rev 1.10 refers
to vocabulary names as:

   For vocabulary ...

   http://isegserv.itd.rl.ac.uk/VM/http-examples/example1

   ... defining classes ...

   http://isegserv.itd.rl.ac.uk/VM/http-examples/example1#ClassA
   http://isegserv.itd.rl.ac.uk/VM/http-examples/example1#ClassB

i.e. the trailing '#' is consistently omitted from the vocabulary name.

I claim this is a fundamental mistake and would argue it on the
basis of both semantics and what the RDF core specifications
state.  The semantic point is that [1] should be the name of the
vocabulary while [2] is the name of a document that might (should)
describe that vocabulary.

[1] http://isegserv.itd.rl.ac.uk/VM/http-examples/example1#
[2] http://isegserv.itd.rl.ac.uk/VM/http-examples/example1

I believe that the terms "namespace name" and "vocabulary
name" should be considered synonymous when they apply
to URI references for use within the Semantic Web.

This is certainly related to the discussion thread [3] (continued
at [4], [5], and [6]) but I hope we can resolve this without forking
those threads yet again.

The RDF core specifications state [7] that RDF URI references
are constructed by simple concatenation of the local name to
the namespace name.  There is nothing in the RDF specifications
that endorse an inference that clients should insert a '#' under
some conditions.

The RDF specification [8] uses the phrasing

  "The RDF namespace URI reference (or namespace name) is
   http://www.w3.org/1999/02/22-rdf-syntax-ns# ... The RDF Vocabulary
   is identified by this namespace name ..."

So it is a mistake for us to suggest in this cookbook that clients
add a "missing" '#'.

(I will raise a similar issue with respect to the SKOS Working Draft
in a separate message.)

I'd noticed this in the 2005-11-18 editor's draft [9] and thought it was
simply a typo so I corrected it in rev 12.  That change was subsequently
reverted in rev 15 but I can't tell from your commit comment whether
you'd intentionally reverted it or not.  So I don't know whether you mean
to draw some distinction here -- and if so we'd better explain that 
distinction with more words -- or whether simply adding the trailing
'#' to the vocabulary names is acceptable to you.

[3] http://lists.w3.org/Archives/Public/public-swbp-wg/2006Jan/thread.html#msg113
[4] http://lists.w3.org/Archives/Public/public-swbp-wg/2006Jan/thread.html#msg129
[5] http://lists.w3.org/Archives/Public/public-swbp-wg/2006Feb/thread.html#msg6
[6] http://lists.w3.org/Archives/Public/public-swbp-wg/2006Feb/thread.html#msg0

[7] http://www.w3.org/TR/rdf-syntax-grammar/#section-Identifiers
[8] http://www.w3.org/TR/rdf-syntax-grammar/#section-Namespace

[9] http://www.w3.org/2001/sw/BestPractices/VM/http-examples/2006-01-18/

-Ralph
Received on Tuesday, 14 February 2006 16:58:45 UTC

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