Message Exchanges are an enumerated list of concrete message exchanges which may be used in conjunction with the test assertions to group, and reveal the coverage of Web Service Addressing 1.0 test cases. This version only has HTTP as the underlying protocol and therefore doesn't expose sceanrios involving a one-way transport, such as Email. The list of WSDL 1.1 bindings, WSDL 2.0 MEPs, SOAP MEPs and SOAP bindings which may be used to describe each exchange are not yet cited.