Integrated Services Digital Network (ISDN); Direct Dialling In (DDI) supplementary service; service description; english version ETS 300062:1991
Edition 1992-09

Integrated Services Digital Network (ISDN); telephony 3,1 kHz teleservice; service description; english version ETS 300111:1992
Edition 1993-04

Integrated Services Digital Network (ISDN); Call Hold (HOLD) supplementary service; functional capabilities and information flows; english version ETS 300140:1992
Edition 1992-12

Private Telecommunications Network (PTN) - Method for the specification of basic and supplementary services; English version ETS 300387:1994
Edition 1994-11

European digital cellular telecommunications system (Phase 2) - Bearer services supported by a GSM Public Land Mobile Network (PLMN); English version ETS 300501:1994
Edition 1995-01

European digital cellular telecommunications system (Phase 2) - Location registration procedures; English version ETS 300530:1994
Edition 1995-01

European digital cellular telecommunications system (Phase 2) - Mobile Station - Base Station System (MS-BSS) interface - General aspects and principles; English version ETS 300550:1994
Edition 1995-01

European digital cellular telecommunications system (Phase 2) - GSM Public Land Mobile Network (PLMN) access reference configuration; English version ETS 300551:1994
Edition 1995-01

European digital cellular telecommunications system (phase 2) - Line identification supplementary services, stage 3; English version ETS 300565:1995
Edition 1995-08

European digital cellular telecommunications system (phase 2) - Unstructured Supplementary Service Data (USSD), stage 3; English version ETS 300572:1995
Edition 1995-08