- From: Dan Brickley <danbri@danbri.org>
- Date: Fri, 26 Jun 2009 19:27:26 +0200
- To: Larry Masinter <LMM@acm.org>
- CC: 'Pat Hayes' <phayes@ihmc.us>, 'Eran Hammer-Lahav' <eran@hueniverse.com>, 'Dan Connolly' <connolly@w3.org>, apps-discuss@ietf.org, www-tag@w3.org, 'URI' <uri@w3.org>
On 26/6/09 18:54, Larry Masinter wrote:
> # They aren't being treated differently. The normal syntax for naming
> # something in RDF is a URI reference with a fragid attached. The use of
> # a fragID cancels any assumptions that the URIreference denotes
> something connected with the HTTP protocol.
>
> How does it do that?
>
> # This is how RDF manages to
> # refer to galaxies, chemical elements, people, etc..
>
> Sounds like this is only in the context of RDF.
Yes and no.
Here's the "Yes": the idea is that if content is served as
application/rdf+xml then the meaning of #foo is delegated to the
relevant spec (http://www.w3.org/2001/sw/RDFCore/mediatype-registration
? humm that's expired). The RDF mediatype doc says
"""Section 4.1 of the URI specification [6] notes that the semantics
of a fragment identifier (part of a URI after a "#") is a property of
the data resulting from a retrieval action, and that the format and
interpretation of fragment identifiers is dependent on the media type
of the retrieval result.
However, in RDF, the thing identified by a URI with fragment
identifier does not bear any particular relationship to the thing
identified by the URI alone. This differs from some readings of the
URI specification [6], so attention is recommended when creating new
RDF terms which use fragment identifiers."""
Here the "No": A URI that points to an RDF document constructed in this
fashion, is (according to those persuaded this story works) supposed to
be a URI for whatever galaxy, chemical element, person etc. the RDF is
structured to represent.
In this way, http://danbri.org/foaf.rdf#danbri is a URI for me. Not just
for RDF applications, but for any applications that care about the idea
of URIs being URIs *for* things. The media-type registration that makes
this so RDF-specific (RDF/XML-specific even) but the URI is supposed to
be a URI for me, full stop, rather than "a URI for me, in RDF applications".
At this point people normally bring up the possibility of clashes across
content-negotiated representations served at the same URI. The usual
answer offered by return is "if that hurts, don't do it".
Dan
Received on Friday, 26 June 2009 17:28:10 UTC