"This Recommendation is part 1 of a multi-part deliverable covering message waiting indication (MWI) using IP multimedia (IM) core network (CN) subsystem ?C Part 1: Protocol implementation conformance statement (PICS)@ as identified below: Part 1: ""Protocol implementation conformance statement (PICS)""; Part 2: ""Test suite structure and test purposes; Network side""; Part 3: ""Test suite structure and test purposes (TSSTP); User side""."