TAG Request for Change to WS Addressing Core

Promoting effective use of the World Wide Web is of course the raison 
d'être of the W3C and of the TAG in particular.  So, it's worth some care 
to ensure that every W3C Recommendation integrates well with the Web.  The 
use of a single naming mechanism (URI) for all resources is key to the 
network effects that underly the extraordinary success of the Web[1], and 
so the TAG pays particular attention to ensuring that Recommendations make 
appropriate use of URIs. 

WSA End Point References [2] contain an [address] property which is a URI 
[3], but the TAG is concerned that other non-URI properties will also 
sometimes be used for resource identification.  We also have come to 
understand that there are practical reasons why the Web Services community 
finds XML-based, QNamed parameters to be powerful and convenient, and that 
those advantages sometimes extend to their use for identification.  For 
example, we are aware that there is a large body of widely deployed 
software that aids in the creation and processing of SOAP headers, 
including those resulting from bound EPR parameters.  Taking all these 
factors together, the TAG today resolved to ask that the Web Services 
Addressing Working Group include the following note in a suitable section 
of the Web Services Addressing 1.0 - Core Proposed Recommendation:

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Note: Web Architecture dictates that resources should be identified with 
URIs.  Thus, use of the abstract properties of an EPR other than 
wsa:address to identify resources is contrary to Web Architecture.  In 
certain circumstances, use of such additional properties may be convenient 
or beneficial, perhaps due to the availability of QName-based tools.  When 
building systems that violate this principle, care must be taken to weigh 
the tradeoffs inherent in deploying resources that are not on the Web.
-----

We hope that this strikes a reasonable balance between promoting effective 
use of the Web, and recognizing the other factors that appropriately 
contribute to design and implementation choices.  FYI, discussion of other 
aspects of TAG issue endPointRefs-47 [4] is ongoing.  We welcome followup 
discussion on the public www-tag@w3.org mailing list.

Thank you very much.

Noah Mendelsohn
For the W3C Technical Architecture Group

[1] http://www.w3.org/TR/webarch/#uri-benefits
[2] http://www.w3.org/TR/2005/CR-ws-addr-core-20050817/#eprs
[3] http://www.w3.org/TR/2005/CR-ws-addr-core-20050817/#eprinfomodel
[4] http://www.w3.org/2001/tag/issues.html#endPointRefs-47


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Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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