URIs and IRIs

Hello Henry,


As you are aware, The SML team has been reviewing the Technical Notes
that will be published in conjunction with the SML specifications.
Monday we reviewed the EPR note: please see comment #18 to issue 5341:
http://www.w3.org/Bugs/Public/show_bug.cgi?id=5341#c18, specifically the
accompanying attachment (in PDF:


One of the points focused on the following phrase (in section 2.1,
bullet 3):


     Since the URI (IRI) in the wsa:Address element of the EPR
identifies only an endpoint of a service. . .


The "URI (IRI)" needs further editing.  The general question is, How
should the note deal with the relationship between URIs and IRIs?  As of
the call on Monday, the thought was to delete the parenthetical
reference to IRIs, since it is the only place in the Note (and spec !)
where IRIs are referred to.  But we wanted to check with you before
making any change.  


Indeed, after further investigation, I believe dropping the IRI here is
the wrong thing to do.  According to the WS-A spec, the value of the
abstract property [address] is defined to be an IRI.  In fact, it seems
that the WS-A moved from talking about URIs (in the Member Submission)
in the abstract information model of an EPR to talking about IRIs in the


A more concrete proposal, on which I would appreciate your thoughts, is:


1.    Refer to IRIs for things pertaining to EPRs, which include values
for the wsa:address and wsa:action elements.  The sentence above would
be "Since the IRI in the wsa:Address element...."

2.    Use "URI" (1) where an actual example of a URI is provided, e.g.,
in the context, "the URI http://www....", and (2) for things pertaining
to the SML specs (reference scheme URIs, aliases).

3.    Text would need to be added in the section on Interoperability to
recognize that IRIs in EPRs must be mapped to URIs in generating aliases
and/or target-complete identifiers


You might also recall a  sentence from the EPR note, which was discussed
on one of the previous calls (you engaged in that discussion).  The
sentence, as currently revised, is:


      However, not all documents or document fragments can be retrieved
simply by means of a URI that may be dereferenced. 


Since this sentence deals with general addressability, I believe it
should also refer to an IRI rather than a URI.  Would you agree?


Thank for your assistance in this mater.



Kirk Wilson, Ph.D.

CA, Inc.

Research Staff Member, CA Labs

Council for Technical Excellence

Tele: 603 823 7146  (preferred)

Cell: 603 991 8873

Fax: 603 823 7148

kirk.wilson@ca.com <mailto:kirk.wilson@ca.com> 


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Received on Tuesday, 3 March 2009 18:59:05 UTC