W3C Architecture Domain | Web Services Activity

Semantic Annotations for WSDL Working Group Charter

Jacek Kopecky (DERI), Chair
Carine Bournez, Eric Prud'hommeaux, Team Contacts

The Working Group follows the rules and requirements of the latest operative version of the World Wide Web Consortium Process Document. In the event of a conflict between this document and the W3C Process Document, the W3C Process Document shall take precedence.

Table of Contents

  1. Mission
  2. Scope
  3. Out of scope
  4. Deliverables
  5. Schedule
  6. Duration
  7. Coordination with Other Groups
  8. Related work
  9. Working Group Participation
  10. Meetings
  11. Communication
  12. Confidentialy
  13. Patent Policy

The Semantic Annotations for WSDL Working Group is part of the Web Services and Semantics (WS2) Project in the W3C Web Services Activity.


The Web Services Description Language (WSDL) specifies a way to describe the abstract functionalities of a service and concretely how and where to invoke it. The WSDL 2.0 specification does not include semantics in the description, thus two services can have similar descriptions while totally different meanings.

The objective of the Semantic Annotations for WSDL Working Group is to develop a mechanism to enable annotation of Web services descriptions. This mechanism will take advantage of the WSDL 2.0 extension mechanisms to build a simple and generic support for semantics in Web services.


The selection of a Web service among several ones with similar WSDL descriptions requires more information than what WSDL 2.0 actually defines. For example, a service with an operation using an in-out pattern, where the input and output messages are elements amount and tax, both of type xs:double, could have different meanings: calculation of tax on a product, calculation of income tax, etc. The Semantic Annotations for WSDL Working Group is chartered to define one or more properties of WSDL 2.0 components to point to additional semantics to concepts represented by those components, e.g. interface, operation, endpoint. Additionally, the Working Group may define annotations to the schema structure to point to external semantics.

The Semantic Annotations for WSDL Working Group will also provide a mapping of the new properties into an RDF form compatible with the RDF mapping for WSDL defined by the WSD Working Group. The Working Group may also continue the work of this RDF Mapping for WSDL 2.0 along the W3C Recommendation track, which would be included in the W3C Recommendation for Semantic Annotations in WSDL.

The Semantic Annotations for WSDL Working Group may discuss the need for semantics at the WSDL 2.0 binding element level.

The Semantic Annotations for WSDL Working Group may define an appropriate syntax for use of its Annotations specification with WSDL 1.1.

Out of scope

This Working Group is not chartered to:

  1. build a full-featured Semantic Web Services framework, e.g. supporting Web services discovery, composition, relocation, etc.
  2. add semantics for components that WSDL 2.0 does not define in its component model.
  3. discuss expression of Web services constraints and capabilities, including precondition and effect.
  4. define a new semantic data model or format for externally defined semantics.

The optional SOAP 1.2 Action media-type parameter and the related WSDL 2.0 wsoap:action element and WS-Addressing 1.0 [action] message addressing property potentially convey semantics when using SOAP bindings. In case the Working Group concludes positively on the need to define semantics on the WSDL binding element, such work must happen under a new charter.


The Working Group is expected to produce a W3C Recommendation for Semantic Annotations in WSDL.


The following milestones are proposed:

March 2006
Working Group created
April 2006
First face–to–face meeting.
September 2006
Last Call Working Draft.
November 2006
Candidate Recommendation.
January 2007
Proposed Recommendation.
March 2007


The expiration date of this charter is 30 June 2007.

Coordination with Other Groups

The Working Group should coordinate its efforts with W3C Working Groups, in particular in the Web Services Activity and the Semantic Web Activity:

Coordination will be managed through the Web Services Coordination Group.

Related work

A Member Submission, WSDL-S, related to this work, has been acknowledged by W3C and should be used as one input to the Working Group.

The OWL-S submission to W3C defines OWL-S extensions to WSDL, to link some WSDL 1.1 constructs to the OWL-S Grounding.

Working Group Participation

To become a member of the Semantic Annotations for WSDL Working Group, a representative of a W3C Member organization must be nominated by their Advisory Committee Representative.

Participation is also open to invited experts from the community, selected by the chair and approved by the W3C Director, in accordance with the Invited Experts provisions in the Process Document, in order to balance the technical experience of the group.

Effective participation is expected to consume one workday per week for each Working Group participant. The Chair shall ensure that the criteria for Good Standing are understood and followed.


The initial chair of this Working Group is Jacek Kopecky (DERI).

W3C Team resources

The initial W3C Team contacts are Carine Bournez and Eric Prud'hommeaux. It is expected that this Working Group will consume about 1 FTE, including administrative logistics.


The Working Group will have distributed meetings, one to two hours every week, and face–to–face meetings, every two to three months.


The Working Group will utilize a public mailing list public-ws-semann@w3.org for its technical email communications. It is referred to in the rest of this document as the Working Group mailing list.

A Member-only mailing list member-ws-semann@w3.org is available for administrative purposes only.


The proceedings of this Working Group are public, subject to exceptions made by the Chair, after consultation with the Working Group.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). 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.

Carine Bournez
Last modified $Date: 2006/03/21 15:43:23 $