After an email exchange with Anish about my previous blog entry I would like to clarify what I wrote on Sunday. I agree that EPRs can be used as identifiers. Just like phone numbers. For example, a specification could require that the Reference Properties be constituted of the element, in effect making the EPR an identity representation by virtue of containing one. And this is fine.
My point is not that this should not be done, it is that the WS-Addressing working group does not need to concern itself with, or even acknowledge this usage of EPRs. The Ws-Addressing working group should concentrate on producing an XML element to package the information necessary to invoke a Web service endpoint. This is what is asked of it. Considering whether and how this can be used for identity consideration is at best a waste of time and at worst a source of unneeded complexity and formalism. Keep it simple.
Note: the most alert readers will have noticed that the prefix of the namespace for the MUWS ResourceId element has changed between my entry on Sunday and this entry from “muws-xs” to “muws-xs-1”. Looks like a detail but this is a sign of an important and very cool improvement that was decided by the WSDM TC today. I am implementing this change in the MUWS spec right now (this blog entry is my little “pause” from the editing work, scary as it sounds). Stay tuned for more. WSDM 1.0 is coming soon to a printer (and a JVM) near you.