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Proposed rewrite for section 3.1

From: Henry S. Thompson <ht@inf.ed.ac.uk>
Date: Thu, 20 Mar 2008 18:46:35 +0000
To: Richard Cyganiak <richard@cyganiak.de>, leo.sauermann@dfki.de
Cc: www-tag@w3.org
Message-ID: <f5babktkzck.fsf@hildegard.inf.ed.ac.uk>

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I've had a quick try at redrafting section 3.1 of https://gnowsis.opendfki.de/repos/gnowsis/papers/2006_11_concepturi/html/cooluris_sweo_note.html#distinguishing

3.1 Distinguishing between representations and descriptions

Above we assumed that there is a distinction between accessing web
documents on the one hand and accessing descriptions of resources on
the other. The question is where to draw the line between the case
where either is possible and the case where _only_ descriptions are
available..

According to W3C guidelines ([AWWW], section 2.2.), we have a Web
document which we can access directly (there called information
resource) if all its essential characteristics can be conveyed in a
message. Examples are a Web page, an image or a music recording. The
URI identifies both the entity and indirectly the message that conveys
the characteristics. There are of course also entities whose
characteristics can not be conveyed in a message.  For such entities,
_only_ descriptions of the entity are available for retrieval It's
crucial to not be confused by the fact that a Web document may itself
often describes some other entity, which is not itself a Web
document. For example the person Alice (not a Web document) is
described by her homepage (a Web document). Bob may not like the look
of the homepage, but fancy the person Alice.

Since our advice above is to only use a 200 response code when a Web
document has been accessed, it follows that when designing URIs and
configuring web servers we need to know when we're talking about
identifying Web documents as such and when we're talking about
descriptions of entities, whether they are Web documents or not.

Our recommendation is to err on the side of caution: Whenever an
object of interest is not clearly and obviously a document (all its
essential characteristics can be conveyed in a message), then it's
better _not_ to respond with a 200 to a request for the URI
identifying it.

[Hmm, this is probably useless, but maybe it helps a bit]
- -- 
 Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                     Half-time member of W3C Team
    2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
            Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
                   URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged spam]
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Received on Thursday, 20 March 2008 18:47:19 GMT

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