Symbol,Reference
itu-t88,[ITU-T Q.761-4 (1988)]
itu-t92+,[ITU-T Q.761-4 (1992)]
ansi88,"[ANSI T1.113-1988 (""Signaling System Number 7 (SS7) - ISDN User Part"")]"
ansi00,[ANSI T1.113-2000]
etsi121,"[ETS 300 121 (""Integrated Services Digital Network (ISDN)"" Application of
the ISDN User Part (ISUP) of CCITT Signalling System No. 7
for international ISDN interconnections (ISUP version 1).)]"
etsi356,"[ETS 300 356-1 (""Integrated Services Digital Network (ISDN)""; Signalling
                 System No.7; ISDN User Part (ISUP) version 2 for the international
                 interface.)]"
ttc87,[JT-Q761-4(1987-1992)]
ttc93+,[JT-Q761-4(1993-)]