This European Telecommunication Standard (ETS) specifies the following Identification Supplementary Services: Calling Line Identification Presentation (SS-CLIP)@ Connected Line Identification Presentation (SS-COLP) and Calling/Connected Line Identification Restriction (SS-CLIR)@ which are applicable to various basic services supported by Private Telecommunication Network (PTN). Basic services are specified in ETS 300 171. Service specifications are produced in three Stages@ according to the method described in ENV 41005. This standard contains the Stage 1 and Stage 2 specifications of the Identification Supplementary Services. The Stage 1 specifications (clauses 5 to 13) specify the supplementary services as seen by users of PTNs. The Stage 2 specifications (clauses 14 to 28) identify the functional entities involved in the supplementary services and the information flows between them.