Web Services Conversation Language (WSCL)
Web Services Conversation Language (WSCL) allows the business level conversations or public processes supported by a Web service to be defined. WSCL specifies the XML documents being exchanged, and the allowed sequencing of these document exchanges. WSCL conversation definitions are themselves XML documents and can therefore be interpreted by Web Services infrastructures and development tools.
Hewlett-Packard submitted WSCL to W3C. See WS Choreography Description Language (CDL).
More information: WSCL page on the W3C website
More on the general topic: WS Choreography Description Language (CDL)