WSDL Conformance and Optional Operations

I asked around and was directed toward a W3C specification in the Web 
Services area that sets a precedent for specifying optional operations in 
WSDL.

One example is the specification for PUT in WS-Transfer (  
http://www.w3.org/2002/ws/ra/edcopies/wst.html#Put ), What's more, the 
specification provides a WSDL that defines all operations in a single 
interface, including the optional operations.

I would propose, then, for protocol that we could define a single 
interface with both the query and update operations and have language in 
the protocol document stating something like: A conforming service 
provider MUST provide one of the following implementations of the 
SparqlProtocol interface:
1. The query operation
2. The update operation
3. Both the query and update operations.

David Charboneau
dcharbon@us.ibm.com