This second part of ETS 300 055 is applicable to the stage three of the Terminal Portability (TP) supplementary service for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T reference point or coincident S and T reference point (as defined in ITU-T Recommendation I.411 [10]) by means of the Digital Subscriber Signalling System No. one (DSS1) protocol. Stage three identifies the protocol procedures and switching functions needed to support a telecommunications service (see CCITT Recommendation I.130 [9]). This ETS provides the Protocol Implementation Conformance Statement (PICS) proforma for the ISDN DSS1 TP supplementary service protocol as specified in ETS 300 055-1 [1] in compliance with the relevant requirements and in accordance with the relevant guidance given in ISO/IEC 9646-7 [8]. The supplier of a protocol implementation which is claimed to conform to ETS 300 055-1 [1] is required to complete a copy of the PICS proforma provided in annex A of this ETS and is required to provide the information necessary to identify both the supplier and the implementation.