This International Standard specifies the Wireless Terminal Location Registration supplementary service (SS-WTLR) and the Wireless Terminal Information Exchange additional network feature (ANF-WTINFO), which are applicable to various basic services supported by Private Integrated Services Networks (PISN). Basic services are specified in ISO/IEC 11574. The Wireless Terminal Location Registration Supplementary Service (SS-WTLR) enables a WTM user to register at, or de-register from, the current location within the PISN. The ability to register at different locations in the PISN at different times enables the WTM user to maintain the provided services (including the ability to make and receive calls) at different access points. De-registration is used to inform the PISN that the WTM user is temporarily unable to make use of the provided services (including the receipt of incoming calls). The Information Exchange Additional Network Feature (ANF-WTINFO) allows to exchange information about a WTLR user between the Home Data Base and the Visitor Data Base. Supplementary service and additional network feature specifications are produced in three stages, according to the method described in CCITT Recommendation I.130. This International Standard contains the stage 1 and stage 2 specifications of SS-WTLR and ANF-WTINFO. The stage 1 specification (clause 6 and 7) specifies the service/feature as seen by users of PISNs. The stage 2 specification (clause 8 and 9) identifies the functional entities involved in the service/feature and the information flows between them.