W3C has chartered a new Web Services Addressing Working Group as part of the W3C Web Services Activity, under the W3C Architecture Domain. The TC Chair is Mark Nottingham (BEA), while Hugo Haas and Philippe Le Hégaret have been designated as W3C Team Contacts. The charter extends through 28-February-2006.

The goal of the new Working Group is to produce a W3C Recommendation for Web Services Addressing by "refining the W3C Member Submission WS-Addressing based on consideration of the importance of this component in the Web Services architecture, implementation experience, and interoperability feedback. WS-Addressing defines how message headers direct messages to a service or agent, provides an XML format for exchanging endpoint references, and defines mechanisms to direct replies or faults to a specific location."

In August 2004 a revised Web Services Addressing (WS-Addressing) specification was presented to W3C as a Member Submission by BEA, IBM, Microsoft, SAP AG, and Sun Microsystems. WS-Addressing "provides transport-neutral mechanisms to address Web services and messages. Specifically, the specification defines XML elements to identify Web service endpoints and to secure end-to-end endpoint identification in messages. The specification enables messaging systems to support message transmission through networks that include processing nodes such as endpoint managers, firewalls, and gateways in a transport-neutral manner."

The new W3C Web Services Addressing Working Group has been chartered to "standardize the mechanisms for referencing and addressing Web services by refining WS-Addressing, which includes four principal components of the W3C's Web Services Architecture specification. These referencing and addressing mechanisms are (1) a means by which message headers are used to direct messages to a Web service or agent; (2) abstract message properties (message identifier; a URI for the destination address; a URI designating the action to be taken at the destination; correlation with other message[s]; the nature of the relationship with those messages) (3) an appropriate XML Infoset definition; (4) abstract properties to identify subsequent destinations in the message exchange, including the reply destination and the fault destination."

The XML Infoset required for "communicating the information necessary to generate appropriate headers to direct messages to a service or an agent includes a URI designating the destination address; service specific message headers; interaction specific message headers; WSDL definitions relevant to this service; additional metadata as required."

According to the WG Charter, these components "must be extensible to enable other mechanisms such as new kinds of relationships between correlated messages, policies, or service semantics to be built upon Web Services Addressing. The components must also be usable independently of the SOAP or WSDL version in use."

Additionally, the WG will define SOAP 1.1 and WSDL 1.1 bindings (defined for backward compatibility only). It will define (1) a binding of all abstract message properties to SOAP 1.1 and SOAP 1.2 headers, (2) the use of these abstract message properties in the context of all WSDL 1.1 or WSDL 2.0 Message Exchange Patterns, including the asynchronous use of these MEPs; in particular, the relationship between message properties and WSDL 1.1 and WSDL 2.0 service descriptions will be provided if applicable, and (3) a security model for using and communicating these abstract properties."

The specified deliverables of the Working Group include a W3C Recommendation for the Web Services Addressing specification; a W3C Recommendation for the Web Services Addressing SOAP 1.1 and SOAP 1.2 Binding specification, mapping Web Services Addressing message properties to SOAP 1. 1 and SOAP 1.2 headers; a W3C Recommendation for the Web Services Addressing WSDL 1.1 and WSDL 2.0 Binding specification, defining the use of Web Services Addressing components in WSDL 1.1 and WSDL 2.0 message exchange patterns and providing the mechanisms for defining Web Services Addressing property values in WSDL 1.1 and WSDL 2.0 service descriptions; a test suite intended to promote implementation of the Candidate Recommendation and to assess interoperability between four interoperable implementations.

The W3C Web Services Addressing Working Group will coordinate with other W3C Groups, especially with those Working Groups involved in the Web Services Activity: XML Protocol Working Group, Web Services Description Working Group, Web Services Choreography Working Group, and Web Services Coordination Group. The specification defined by the Web Services Addressing Working Group will also "be aligned with the World Wide Web architecture as defined by the Technical Architecture Group (TAG), e.g., for mapping qnames to URIs. The WG will coordinate with relevant OASIS TCs and with the Web Services Interoperability Organization (WS-I).

The Working Group has been chartered to operate under the W3C Patent Policy of 5-February-2004; "to promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis."