3.7.4.4 Add/Modify/Delete Group
Similarly to managing contacts, managing groups within the contact list is done through modifyGroup, and deleteGroup SOAP requests carried in a SIP SERVICE request from the client to the server. Groups are identified in these requests by an integer (1-63). A contact can belong to one or more groups. Every contact belongs to group #1 by default. This is the default group created automatically by the server, and MUST NOT be created or deleted by the user.
Before a group can be deleted, all contacts must be removed from the group by using DeleteContact operations. The associated XML schema for these operations is specified in Appendix D: Contact Management Schema (section 9).
The server indicates that a modifyGroup request or a deleteGroup request was successful by sending a 200 OK response to the SERVICE request.