3.7.4.3 Add/Modify/Delete Contact
Adding, modifying, or deleting a contact is done through setContact and deleteContact SOAP requests carried within a SIP SERVICE verb from the client to the server. Note that in all of these SERVICE requests, the To URI, From URI, and Request-URI are the SIP URI of the user (not the contact). The associated XML schema for these common operations is specified in Appendix D: Contact Management Schema (section 9).
The server indicates that a setContact or a deleteContact request was successful by sending a 200 OK response to the SERVICE request.