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FOAF namespace info Re: [VM] Telecon Tuesday 25 Oct - schedule for Friday?

From: Dan Brickley <danbri@w3.org>
Date: Tue, 25 Oct 2005 12:13:07 +0100
Message-ID: <435E1343.7090607@w3.org>
To: Thomas Baker <tbaker@tbaker.de>
Cc: SW Best Practices <public-swbp-wg@w3.org>

Thomas Baker wrote:

>Vocabulary Management telecon, Tue, Oct 25, 1300 UTC (1500 Berlin)
>Zakim: +1.617.761.6200=20
>Conference code 8683# ('VMTF')
>Dear all,
>We had our last telecon on 27 September [1] and are scheduled
>to have another one this afternoon at 1300 UTC.  I will dial in 
>at that time.  However, I would prefer to schedule a call for
>later this week:
>-- Dan cannot make it today, but know that he is working on his 
>   action [2];
>[2] http://www.w3.org/2005/09/27-vmtf-minutes.html#action01



I have an action from the Vocabulary Management task force of the W3C SW 
Best Practices <http://www.w3.org/2001/sw/BestPractices/> Working Group 
to document the way the FOAF namespace currently works. Here goes.

The FOAF RDF vocabulary is named by the URI http://xmlns.com/foaf/0.1/ 
and has information available at that URI in both machine-friendly and 
human-friendly form. When that URI is dereferenced by HTTP, the default 
representation is currently HTML-based.

Aside: I say /based/ because the markup, while basically being XHTML, 
also includes incline RDF/XML describing the FOAF vocabulary. The HTML 
TF of SWBPD WG is looking at ways of making such documents validatable; 
I hope a future version will be valid in some way, as well as 
presentable in mainstream browsers. This might be via RDF/A in XHTML2, 
RDF/A back-ported to an early XHTML variant, a GRDDL-based transform, or 
perhaps a CDF document if they’re deployable in legacy browsers.

Backing up to the big picture: we want to make it easy for both people 
and machines to find out what they need. So the basic idea is that 
there’s an HTML document describing FOAF for humans, and a set of RDF 
statements describing FOAF for machines. The RDF statements are 
available in several ways. As embedded RDF/XML in the HTML page. As a 
separate index.rdf <http://xmlns.com/foaf/0.1/index.rdf> document (this 
should be LINK REL’d from the former), and as a content-negotiable 
representation of the main URI, available to clients that send an 
“Accept: application/rdf+xml” header.

In addition to this, each FOAF term (assuming the Apache .htaccess is up 
to date; this might not be currently true) is redirected by the Web 
server to the main FOAF namespace URI. For example, 
http://xmlns.com/foaf/0.1/Person. This should in the future be done with 
a 303 HTTP redirection code, to be consistent with the recent W3C TAG 
decision on http-range-14 (apologies for the jargon and lack of links to 
explanation). Because FOAF term URIs don’t contain a /, note that the 
redirection can’t point down into a sub-section of the HTML document. To 
make the HTML document more usable, we should probably put a better 
table of contents for terms nearer to the top of the page, to allow 
someone to navigate quickly to the description of that term.

One last point: each term defined in FOAF is accompanied not only by a 
label and comment (standard from RDFS); it also has a chunk of HTML 
markup, with cross-references to other terms. At the moment, this is not 
made available in any machine-readable form. There might be some scope 
here for common practice with SKOS and other vocabularies?

Sorry for the hasty writeup, I just wanted to get this recorded as a 
starting point…

Received on Tuesday, 25 October 2005 11:13:19 UTC

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