[foaf-dev] foaf phone and tel URLs

Axel Polleres axel.polleres at deri.org
Wed Jan 30 18:21:01 GMT 2008

I agree that using URI's for telephone numbers is a pain, especially 
when mapping from/to other voacabularies...
The problem is:

rdf:Resource owl:differentFrom xsd:anyURI .

Especially, we had trouble with this when trying to map from vCard 
to/from foaf, we tried with sparql, but even if you'd imagine you had 
more powerful buiilt-ins in sparql. say the whole palette of 
Xquery/xPath, you wouldn't be able to convert between a string encoded
tel and a URI... literals are different from resources and there is no 
way to vonvert between them.

For more details see

  Axel Polleres, François Scharffe, and Roman Schindlauer. SPARQL++ for 
mapping between RDF vocabularies. In OTM 2007, Part I : Proceedings of 
the 6th International Conference on Ontologies, DataBases, and 
Applications of Semantics (ODBASE 2007), volume 4803 of Lecture Notes in 
Computer Science, pages 878-896, Vilamoura, Algarve, Portugal, November 
2007. Springer.

and the presentation slides for that paper:


Story Henry wrote:
> I was reading the tel: spec
> http://www.ietf.org/rfc/rfc2806.txt
> It looks like their definition of a tel URI is context dependent in many 
> cases. Ie. that is not what I would call a URI, understood as a 
> Universal Resource Identifier. Of course some people want to think that 
> URIs are "Uniform Resource Identifiers", but well that breaks a lot of 
> web conventions. If one has to take the context of where a URI is 
> asserted into account to understand its meaning, then it is not very 
> useful in any setting where information needs to be merged, most of all 
> the semantic web.
> Should we limit the tel URIs of foaf:phone to ones that are Universal, 
> ie useable from anywhere on the planet? Or should one specify an 
> indirection context:
> :me foaf:phone [ from [ geo :France ];
>                 call "0164225952";
>               ],
>               [ from [ geo :IbisHotel ];
>                 call "9164225952";
>               ] ...
> No, I don't really want to spend time right now thinking about this. 
> Perhaps the vcard people have. It may be worth a note... Sorry if this 
> has already been discussed before.
>     Henry
> Home page: http://bblfish.net/
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Dr. Axel Polleres
email: axel at polleres.net  url: http://www.polleres.net/

rdf:Resource owl:differentFrom xsd:anyURI .

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