W3C home > Mailing lists > Public > www-tag@w3.org > June 2006

RE: CURIEs: A proposal

From: Misha Wolf <Misha.Wolf@reuters.com>
Date: Mon, 12 Jun 2006 22:10:30 +0100
To: www-tag@w3.org, public-rdf-in-xhtml-tf@w3.org, newsml-2@yahoogroups.com
Cc: Harry Halpin <hhalpin@ibiblio.org>
Message-id: <A29ADE959C70A1449470AA9A212F5D800203F84F@LONSMSXM06.emea.ime.reuters.com>

I'm concerned that people are incorrectly assuming that CURIEs 
address a single set of requirements.  On this mistaken foundation, 
various proposals are developed, which do not satisfy the full set 
of requirements.  I hope to respond to Harry's mail tomorrow.  In 
the meantime, please take a look at my presentation to the W3C AC, 
which summarises the News Industry's requirements:
and at my mail titled "CURIEs: A proposal":

------------------- NewsML 2 resources ------------------------------
http://www.iptc.org         | http://www.iptc.org/std-dev/NAR/1.0
http://www.iptc.org/std-dev | http://groups.yahoo.com/group/newsml-2

-----Original Message-----
From: public-rdf-in-xhtml-tf-request@w3.org [mailto:public-rdf-in-xhtml-tf-request@w3.org] On Behalf Of Harry Halpin
Sent: 09 June 2006 10:37
To: mark.birbeck@x-port.net
Cc: www-tag@w3.org; public-rdf-in-xhtml-tf@w3.org
Subject: Re: CURIEs: A proposal

I think Henry's pointing to the conceptual problem with making CURIEs a
"superset" of QNames.  Unlike CURIEs, QNames (at least as I've been able
to discover, correct me if I'm wrong - the spec just seems silent) do
not define an algorithm for converting an entire QName to a IRI, and by
"algorithm" we're not talking about anything fancy - but just
concatenating the namespace URI and the local name as strings, which is
what most processors do anyways - as pointed out by Borden [1] and
raised to the TAG [2], who seemed to be answer a sort of different
question in their finding.

Yet a processor can map (expanded name, local name)  like
(http://www.w3.org/1999/XSL/Transform,template) to an IRI by doing:


Or by doing:


And it seems both would be equally valid or invalid, depending on your

So by making CURIEs a superset of QNames is a bit difficult as long as
the QName (namespace prefix, local name)=>IRI construction is
unspecified. And so using the ":" for QNames and CURIEs means that given
any "x:y" element or attribute name one couldn't tell whether one meant
an IRI or a (namespace prefix, local name). So there seems to be two

1) Unspecified IRI construction for the entire (namespace prefix, local
name) a *bug* in QNames and should be corrected post-hoc by the CURIE
proposal. If this is the case, then CURIEs should use ":" and then make
themselves a superset of QNames.


2) Unspecified IRI construction in QNames is a *feature*  and so CURIEs
exist as a parallel standard, and so use [insert character besides ":"
here] in order to keep confusion between QNames and CURIEs at a minimum.

 My earlier post is that some communities (i.e. some of the microformat
people I talked to at WWW2006) mentioned that they would like another
character besides : for "namespaces in microformats." Next time I'll
just tell them to escape their colons :)

[1] http://www.openhealth.org/RDF/QNameQuagmire.html
[2] http://www.w3.org/2001/tag/issues.html#rdfmsQnameUriMapping-6


Harry Halpin,  University of Edinburgh 
http://www.ibiblio.org/hhalpin 6B522426

To find out more about Reuters visit www.about.reuters.com

Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Reuters Ltd.
Received on Monday, 12 June 2006 21:11:20 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:32:49 UTC