Existing Wording: The conditional create operation allows a client to create a new resource only if some equivalent resource does not already exist on the server.

Comment:

Allowing a client to make the decisions for the server is problematic as the client may not be aware of all of the conditions and requirements of the server. The server should also be allowed to determine itself what would be considered a duplicative entry regardless of whether the client uses a conditional create or not (If this is allowed by the specification, it should be explicetely stated.