1. A method of offering a service provided by a server computer in a communication network, comprising: sending, from the server computer that provides the service to a client computer, a service description document in a language for describing web services, which is independent of any client or user characteristic, the service description document comprising a description defining the type, content and sequencing of data exchanged between said server and any client when said service is executed, and comprising a description of a processing functionality implemented during a preprocessing or post-processing of data in XML format of a message exchanged during the execution of said service on the communication network, wherein the description of said processing functionality comprises a list of properties supported by said processing functionality, said properties defining at least respectively, the node in the communication network adapted to execute said processing, and the type of processing, wherein the description of said processing functionality comprises a property adapted to specify whether the processing to be carried out is obligatory or optional, and wherein said processing functionality also comprises a property adapted to specify whether said pre-processing is carried out on the reception of said message before executing said service or whether said post-processing is carried out on the sending of said message after executing said service.
1. A method of offering a service provided by a server computer in a communication network, comprising: sending, from the server computer that provides the service to a client computer, a service description document in a language for describing web services, which is independent of any client or user characteristic, the service description document comprising a description defining the type, content and sequencing of data exchanged between said server and any client when said service is executed, and comprising a description of a processing functionality implemented during a preprocessing or post-processing of data in XML format of a message exchanged during the execution of said service on the communication network, wherein the description of said processing functionality comprises a list of properties supported by said processing functionality, said properties defining at least respectively, the node in the communication network adapted to execute said processing, and the type of processing, wherein the description of said processing functionality comprises a property adapted to specify whether the processing to be carried out is obligatory or optional, and wherein said processing functionality also comprises a property adapted to specify whether said pre-processing is carried out on the reception of said message before executing said service or whether said post-processing is carried out on the sending of said message after executing said service. 8. The method according to claim 1 , wherein said processing functionality also comprises a property adapted to define the data produced or used by said preprocessing or post-processing, and may also include the type of said data.