RE: WSD Requirements: add a requirement about safe and idempotent characteristics

>I'm not entirely certain how an idempotent attribute independent of the method helps the requester.  
>What would that software due with this proposed attribute?
 
For example, if the requester is unsure whether the service has received its request, and it knows from the WSDL interface that the request is idempotent (even though it's transmitted over POST), then it could reissue the original request knowing that, even in the case the first request was actually received, this second request would not alter the net effect.
 
Ugo