u201d u201c target address u201d and u201c actions u201d elements and allow the user to manipulate these parameters once the user has finished manipulating the service data the user terminal sends a put request to the as xdms including the xml document containing the modified service data in the communication diversion basic xml schema the as xdms applies the appropriate set of rules or filters to adapt the xml document from the communication diversion basic xml schema to the communication diversion xml schema in which the xml document is stored in the hss the as xdms therefore replaces the u201c ss_basic complex u201d parameter with the original u201c presence status u201d condition this xml document including the modified service data is then stored at the hss if the user then accesses the cdiv service data from a user terminal that supports cdiv based on presence e g via the web portal used to initially configure the service the user will observe that the service data has changed in accordance with the modifications made via the other user terminal fig8 illustrates schematically an example of an as xdms 1 suitable for implementing the method described above the as xdms 1 can be implemented as a combination of computer hardware and software the as xdms 1 comprises a receiver 6 for receiving messages sent from a user terminal over the ut interface a transmitter 7 for sending messages to the user terminal over a ut interface and a processing unit 8 for determining if the structure of an xml document for a service stored at a hss differs from the structure required by or received from a user terminal and if so.