XML News from Tuesday, July 10, 2007

The W3C Web Services Activity. has published the proposed recommendation of Semantic Annotations for WSDL and XML Schema back to last call. According to the draft,

Semantic Annotations for WSDL and XML Schema (SAWSDL) defines how to add semantic annotations to various parts of a WSDL document such as input and output message structures, interfaces and operations. The extension attributes defined in this specification fit within the WSDL 2.0 [WSDL 2.0], WSDL 1.1 [WSDL 1.1] and XML Schema [XMLSchema Part 1: Structures] extensibility frameworks. For example, this specification defines a way to annotate WSDL interfaces and operations with categorization information that can be used to publish a Web service in a registry. The annotations on schema types can be used during Web service discovery and composition. In addition, SAWSDL defines an annotation mechanism for specifying the data mapping of XML Schema types to and from an ontology; such mappings could be used during invocation, particularly when mediation is required. To accomplish semantic annotation, SAWSDL defines extension attributes that can be applied both to WSDL elements and to XML Schema elements.

The semantic annotations reference a concept in an ontology or a mapping document. The annotation mechanism is independent of the ontology expression language and this specification requires and enforces no particular ontology language. It is also independent of mapping languages and does not restrict the possible choices of such languages.