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Re: IRI vs. URI Reference in RDFa

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 19 May 2011 23:53:17 -0500
Cc: RDF Working Group <public-rdf-wg@w3.org>, Manu Sporny <msporny@digitalbazaar.com>, W3C SW CG Group <w3c-semweb-cg@w3.org>
Message-Id: <A43D308B-9B41-43CA-90D6-C278FD4C7676@ihmc.us>
To: Ivan Herman <ivan@w3.org>

On May 19, 2011, at 1:09 AM, Ivan Herman wrote:

> For the records, this is related to ISSUE-8[1]. Note also the advice I got from Felix Sasaki, former member of the Internationalization Activity in the W3C Team[2], which essentially advices to keep the IDN and its punycode equivalent as separate URIs as far as RDF is concerned.

I agree with this.

Pat 


> This seems to be in line with the proposal Manu. Maybe this is the opportunity for the RDF WG to officially close ISSUE-8.
> 
> Ivan
> 
> 
> [1] http://www.w3.org/2011/rdf-wg/track/issues/8
> [2] http://www.w3.org/mid/482F7435-3DD8-4FBB-A568-0D8937B2ED94%2540w3.org
> 
> On May 19, 2011, at 07:33 , Manu Sporny wrote:
> 
>> BCC-cross-posted to: SWCG, RDFa WG
>> 
>> There is an RDF/RDF Web Apps/RDFa coordination issue that the RDF Web
>> Apps group needs to have resolved in order to take RDFa Core 1.1 and
>> XHTML+RDFa 1.1 into Candidate Recommendation. We are requesting input
>> from RDF WG and coordination help from SW CG
>> 
>> The basic question is what should an RDFa processor do when it comes
>> across a value in an HTML document that looks like this:
>> 
>> <a rel="foaf:homepage"
>>  href="http://www.schweizer-küche.de/">Schweizer Küche</a>
>> 
>> The issue is being tracked here (raised by Mischa):
>> 
>> http://www.w3.org/2010/02/rdfa/track/issues/87
>> 
>> We had a very long conversation about it on the telecon last week:
>> 
>> http://www.w3.org/2010/02/rdfa/meetings/2011-05-12#ISSUE__2d_87__3a__IRI_vs__2e__URI_References
>> 
>> So the question is whether or not the markup above should generate this:
>> 
>> <> foaf:homepage <http://www.schweizer-küche.de/> .
>> 
>> or should generate this:
>> 
>> <> foaf:homepage <http://www.xn--schweizer-kche-qsb.de/> .
>> 
>> There were good arguments both ways, but I believe that the RDFa WG
>> settled on the RDFa processor not modifying the URL value when
>> generating the triples for two reasons:
>> 
>> 1) Punycoding URLs could change the meaning of the triple such that
>>  matching rules written by the author would no longer match.
>> 2) Punycoding URLs are culturally imperialistic - most of the world's
>>  primary languages cannot be expressed in ASCII, we shouldn't
>>  force punycoding on all languages "other than English".
>> 3) Modifying URLs away from the authors intent, or away from well-known
>>  transforms like relative-IRI to absolute-IRIs or normalized
>>  IRIs, is bad. We shouldn't attempt to guess what the author meant.
>> 4) IDN is a hack and should be dragged into the street and shot
>>  (ok, so this is just my opinion :P)
>> 
>> So the general assertion is that RDFa Processors should only perform the
>> following transformation on IRIs:
>> 
>> 1. Relative to Absolute IRI transformation.
>> 
>> That is, they shouldn't punycode and they shouldn't attempt to do any
>> other processing on the IRI output by the processor. In other words,
>> RDFa Processors shouldn't second-guess the document author. Thoughts?
>> 
>> -- manu
>> 
>> PS: This also, tangentially, re-opens the can of worms on equivalence
>> testing for IRIs in RDF. Is http://example.com/ros&#xE9 the same as
>> HTTP://example.com/ros%C3%A9 for equivalence testing in RDF?
>> 
>> -- 
>> Manu Sporny (skype: msporny, twitter: manusporny)
>> President/CEO - Digital Bazaar, Inc.
>> blog: PaySwarm Developer Tools and Demo Released
>> http://digitalbazaar.com/2011/05/05/payswarm-sandbox/
>> 
>> 
> 
> 
> ----
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> PGP Key: http://www.ivan-herman.net/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
> 
> 
> 
> 
> 
> 
> 

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Received on Friday, 20 May 2011 04:53:47 GMT

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