Digitale Enhanced Cordless Telecommuncation (DECT) - Date Service Profile (DSP) - Isochronous data bearer services with closed user groups (service type D, mobilityclass 1) (Endorsement of the English version EN 301239 V 1.1.3 (1998-06) as German standard)
Edition 1999-07

Digital cellular telecommunications system (Phase 2) - Closed User Group (CUG) supplementary services - Stage 1 (Endorsement of the English version ETS 300518:1996-05 as German standard)
Edition 2001-04

European digital cellular telecommunications system (Phase 2) - Closed User Group (CUG) supplementary services - Stage 2; English version ETS 300546:1996
Edition 1996-08

Radio Equipment and Systems (RES) - Digital Enhanced Cordless Telecommunications (DECT); Data service profile (DSP) - Generic data link service for closed user groups (service type C, class 1); English Version ETS 300699:1996
Edition 1998-06

Digital cellular telecommunications system (Phase 2) - Closed User Group (CUG) supplementary services - Stage 3 (Endorsement of the English version ETS 300569:1996-11 as German standard)
Edition 2001-04

Integrated Services Digital Network (ISDN) - Signalling System No. 7 (SS7); ISDN User Part (ISUP) version 4 for the international interface - Part 9: Closed User Group (CUG) supplementary service (ITU-T Recommendation Q.735, clause 1 (1993), modified) (Endorsement of the English version EN 300356-9 V 4.1.2 (2001-07) as German standard)
Edition 2002-01

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol; Closed User Group (CUG) supplementary service - Part 5: Test Suite Structure and Test Purposes (TSS&TP) specification for the network (Endorsement of the English version EN 300138-5 V 3.1.1 (2002-04) as German standard)
Edition 2002-12

Integrated Services Digital Network (ISDN) - Closed User Group (CUG) supplementary service; Digital Subscriber Signalling System No. one (DSS1) protocol - Part 1: Protocol specification (Endorsement of the English version EN 300138-1 V 1.3.4 (1998-06) as German standard)
Edition 2000-01

Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling System No. two (DSS2) protocol; closed User Group (CUG) supplementary service - Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification (Endorsement of the English version ETS 300770-2:1998 as German standard)
Edition 2000-01

Integrated Services Digital Network (ISDN) - Closed User Group (CUG) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification (Endorsement of the English version EN 300138-2 V 1.3.4 (1998-06) as German standard)
Edition 2000-01