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Re: URI coordination: blank URIs

From: Graham Klyne <gk@ninebynine.org>
Date: Tue, 22 Apr 2003 21:40:40 +0100
Message-Id: <>
To: pat hayes <phayes@ai.uwf.edu>
Cc: w3c-rdfcore-wg@w3.org

At 11:40 18/04/2003 -0500, pat hayes wrote:
>>This is for information, no action requested.
>>First, the minutes of the URI BOF held at the last IETF meeting are at [1]:
>>Also, there is an issue list [2]
>>[1] http://lists.w3.org/Archives/Public/uri/2003Mar/0043.html
>>[2] http://www.apache.org/~fielding/uri/rev-2002/issues.html
>>And so to the blank URI question:
>>I was reminded obliquely (by a comment about splitting URIs into QNames 
>>in Jena) that the folks looking at RFC2396bis (URI spec revision) have 
>>raised the issue of how to treat fragments attached to blank URIs.
>What is a blank URI?? Does it have anything to do with a blank node in 
>RDF? (I hope not.)

Er, no.  In this context, it's a (relative) URI that happens to be an empty 

I mentioned this because it touches upon the discussion we had a while ago 
(c. Cannes, IIRC) about how to interpret a bare fragment identifier in RDF, 
within the scope of an xml:base declaration.

The suggested revised wording for RFC2396 allows an interpretation of this 
scenario that might be regarded as less surprising than the current 
situation concerning xml:base in RDF.


>>Currently, according to RFC2396, #frag is always relative to the current 
>>document rather than the current URI resolution base.  This caused us 
>>some debate about how to deal with xml:base in RDF.
>>The current thinking in the URI group is to replace this with a 
>>discussion of (non-) retrieval when a bare fragment is used:
>>One cannot use the fragment to indicate relative to a base document,
>>other than to the current document.  Some want to allow XML parsers
>>for RDF to use base URI+fragment together.  The proposal would replace
>>discussion in current document with extended discussion of retrieval
>>when base is same as current document. There was support for this the
>>-- http://lists.w3.org/Archives/Public/uri/2003Mar/0043.html
>>Note that this issue is a request to change the "current document"
>>algorithm.  This can be accomplished by changing the spec to remove
>>the bit about current document and instead replace the empty URI with
>>the base URI, later stating that a retrieval action must not take place
>>if the new URI differs from the base URI only by its fragment.
>>-- http://www.apache.org/~fielding/uri/rev-2002/issues.html#017-rdf-fragment
>>(Actually, I think there's a typo there in the issue list:  the minutes 
>>reflect my understanding.)
>>Graham Klyne
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Graham Klyne
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Tuesday, 22 April 2003 16:44:35 UTC

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