WSDL (Web Services Description Language) Question:

A semantic annotation is additional information in a document that defines the semantics of a part of that document. In this technical note, the semantic annotations are additional information elements in a WSDL document. They define semantics by referring to a part of a semantic model that describes the semantics of the part of the document being annotated.

The WSDL document forms the anchor point for Web services description. Building on the descriptive capability of WSDL, a mechanism is provided to annotate the capabilities and requirements of Web services with semantic concepts referenced from a semantic model. To do this, mechanisms are provided annotate the service and its inputs, outputs and operations. Additionally, we provide mechanisms to specify and annotate preconditions and effects of Web Services.These preconditions and effects together with the semantic annotations of inputs and outputs can enable automation of the process of service discovery.