The present document provides the Implementation Conformance Statement (ICS) pro forma for the Communication Waiting (CW) service@ based on stage 1 and stage 2 of the ISDN call waiting supplementary services defined in ETSI TS 124 615 [1] in compliance with the relevant requirements@ and in accordance with the relevant guidance given in ISO/IEC 9646-7 [4] and ETSI ETS 300 406 [2].