Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 18: Completion of Calls to Busy Subscriber (CCBS) supplementary service [ITU-T Recommendation Q.733, clause 3 (1997), modified]
Edition 2001-11-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 19: Three-Party (3PTY) supplementary service [ITU-T Recommendation Q.734, clause 2 (1996) and implementors guide (1998), modified]
Edition 2001-11-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 20: Completion of Calls on No Reply (CCNR) supplementary service [ITU-T Recommendation Q.733, clause 5 (1999), modified]
Edition 2001-11-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 21: Anonymous Call Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]
Edition 2001-11-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 - ISDN User Part (ISUP) version 3 for the international interface - Part 34: Protocol Implementation Conformance Statement (PICS) proforma specification for supplementary services
Edition 2000-12-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 - ISDN User Part (ISUP) version 3 for the international interface - Part 35: Test Suite Structure and Test Purposes (TSS&TP) specification for supplementary services
Edition 2000-12-01

Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 3 for the international interface - Part 36: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for supplementary services (incl. CD-ROM!!!)
Edition 2003-04-01

Integrated Services Digital Network (ISDN) - Completion of Calls to Busy Subscriber (CCBS) supplementary service - Service description
Edition 2001-08-01

Integrated Services Digital Network (ISDN) - Completion of Calls to Busy Subscriber (CCBS) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 1: Protocol specification
Edition 2000-10-01

Integrated Services Digital Network (ISDN) - Completion of Calls to Busy Subscriber (CCBS) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 2: Protocol Implementation Conformance Statement (PICS) proforma specification
Edition 2001-09-01