Content negotiation: Why always redirect from non-information resource to information resource?

Dear all,

  in the well-known guides on cool URIs and publishing linked data, there is
one thing I don't understand.  When doing 303 redirects, there are always
three URIs/URLs involved:

* U, the URI of the non-information resource (redirects depending on requested
  MIME type)
* U_R, the URL of the RDF information resource
* U_H, the URL of the HTML information resource

I do understand that it makes sense to have separate URLs for U_R and U_H.
Delivering everything, be it RDF or HTML, directly from U (which would
technically be possible) would impair cacheability.

But why can't we do without U_R and do it like this?

* If RDF is requested from U, it is directly served from U
* If HTML is requested from U, a 303 redirect to U_H is made.

I'd be interested in justifications for the above-mentioned best practice
(with 3 URIs/URLs) that are based on semantic considerations and on HTTP
architecture.  Restrictions imposed by Apache's standard plugins are not
relevant to me.

Cheers, and thanks in advance,

Christoph

-- 
Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype duke4701

Received on Tuesday, 26 January 2010 23:46:30 UTC