ABBREVIATIONS SPECIFIC TO SIGNALLING SYSTEM No. 71) 

English	French	Spanish	Meaning	
ACB	ACI	SAP	Access barred signal	
			Table 3/Q.723	
ACC	RAE	CAC	Automatic congestion control information message	
			Table 3/Q.723	
ACM	ACO	MDC	Address complete message	
			Table 3/Q.723, Figure 3/Q.724	
ADI	ADI	SDI	Address incomplete signal	
			Table 3/Q.723, Figure 3/Q.724	
AERM	STEA	MA	Alignment error rate monitor	
			Figures 7–9/Q.703 and 11–17/Q.703	
ANC	RAT	RCT	Answer signal, charge	
			Table 3/Q.723, Figure 3/Q.724	
ANN	RST	RST	Answer signal, no charge	
			Table 3/Q.723	
ANU	RSI	RNC	Answer signal, unqualified	
			Table 3/Q.723	
BIB	BIR	BII	Backward indicator bit	
			Figures 3/Q.703, 13/Q.703 and 15/Q.703	
BLA	BLA	ARB	Blocking–acknowledgement signal	
			Table 3/Q.723	
BLO	BLO	BLO	Blocking signal	
			Table 3/Q.723	
BSM	DE	MPE	Backward set–up message	
			Table 3/Q.723	
BSN	NSR	NSI	Backward sequence number	
			Figures 3/Q.703, 14/Q.703 and 16/Q.703	
BSNR	NSR–R	NSIR	Backward sequence number received	
			Figures 7/Q.703, 13/Q.703, 14/Q.703, 16/Q.703	
BSNT	NSR–E	NSIT	Backward sequence number of next SU to be transmitted	
			Figures 7–9/Q.703 and 13–16/Q.703, Figures 27 and 30/Q.704.	
CBA	RCA	ARS	Changeback acknowledgement signal	
			Table 3/Q.704	
CBD	RCO	ORS	Changeback declaration signal	
			Table 3/Q.704	
CBK	RAC	COL	Clear–back signal	
			Table 3/Q.723, Figure 3/Q.724	

English	French	Spanish	Meaning	
CCF	CCN	FCO	Continuity–failure signal	
			Table 3/Q.723	
CCI	CCE	PCL	Continuity check incoming	
			Recommendation Q.724, § 7.3, Figures 3/Q.724, 5/Q.724	
CCL	RAD	LALN	Calling party clear signal	
			Table 3/Q.723	
CCM	SC	MSC	Circuit supervision message	
			Table 3/Q.723	
CCO	CCS	PCS	Continuity–check outgoing	
			Recommendation Q.723, § 7.3, Figures 3/Q.724, 4/Q.724	
CCR	CCD	PPC	Continuity–check–request signal	
			Table 3/Q.723, Figures 2/Q.724, 3/Q.724, 6/Q.724 and 7/Q.724	
CCS	CS	SCC	Common channel signalling	
			Recommendation Q.701, § 1.1	
CFL	ECH	SLI	Call–failure signal	
			Table 3/Q.723, Figure 3/Q.724	
CGC	EFC	CHC	Circuit–group–congestion	
			Table 3/Q.723, Figure 3/Q.724	
CHG	TAX	MTA	Charging message	
			Table 3/Q.723	
CHM	PR	MPA	Changeover and changeback messages	
			Table 1/Q.704	
CIC	CIC	CIC	Circuit identification code	
			Recommendation Q.704, § 15, Recommendation Q.723, § 2.2.1	
CIR	IDD	PIL	Calling–line–identity–request signal	
			Table 3/Q.723	
CK	CRT	BCE	Check bits	
			Figure 3/Q.703	
CLF	FIN	FIN	Clear–forward signal	
			Table 3/Q.723, Figures 3/Q.724, 6/Q.724, 7/Q.724	
CNM	GRC	GRC	Circuit network management message group	
CNP	CLI	CIM	Connection–not–possible signal	
			Table 1/Q.704	
CNS	CLN	CIN	Connection–not–successful signal	
			Table 1/Q.704	
COA	PCA	APR	Changeover acknowledgement signal	
			Table 1/Q.704	
COO	PCO	OPR	Changeover order signal	
			Table 1/Q.704	
COT	CCP	CON	Continuity signal	
			Table 3/Q.723, Figure 3/Q.724	

English	French	Spanish	Meaning	
CPC	STA	CTL	Call processing control	
			Recommendation Q.724, § 10.2, Figures 1–7/Q.724	
CRI	CRE	RPL	Continuity recheck incoming	
			Recommendation Q.724, § 15.1, Figures 1/Q.724, 2/Q.724, 3/Q.724, 6/Q.724, 7/Q.724	
CRO	CRS	RPS	Continuity–recheck outgoing	
			Recommendation Q.724, § 15.1, Figures 1–3/Q.724, 6/Q.724	
CSM	SA	MSL	Call supervision message	
			Table 3/Q.723	
CSS	CLR	SCF	Connection–successful signal	
			Table 1/Q.704	
DAEDR	DAD–R	DADR	Delimitation, alignment, error detection (reception)	
			Figures 7/Q.703, 9/Q.703, 11/Q.703, 14/Q.703, 16/Q.703, 17/Q.703, 18/Q.703	
DAEDT	DAD–E	DADT	Delimitation, alignment, error detection (transmitting)	
			Figures 12/Q.703, 13/Q.703, 15/Q.703	
DCE	ETCD	ETCD	Data circuit terminating equipment	
			Figure 1/Q.702	
DLC	CLO	CED	Signalling–data–link–connection–order signal	
			Table 1/Q.704	
DLM	CL	MED	Signalling–data–link–connection–order message	
			Table 1/Q.704	
DPC	CPD	CPD	Destination point code	
			Recommendation Q.704, §§ 2.2.3, 13.2, Figure 3/Q.704, 14/Q.704, 26/Q.704, Recommendation Q.706, § 3, Recommendation Q.723, § 2.2.1	
DPN	CNN	TDN	Digital path not provided signal	
			Table 3/Q.723	
DUP	SSUD	PUD	Data user part	
			Recommendation Q.701, § 2.1, Figure 2/Q.701	
ECA	PUA	AER	Emergency changeover acknowledgement signal	
			Table 1/Q.704	
ECM	PU	MEP	Emergency changeover message	
			Table 1/Q.704	
ECO	PUO	PER	Emergency changeover order signal	
			Table 1/Q.704	
EUM	EXT	IAL	Extended–unsuccessful–backward set–up information message indication	
			Table 3/Q.723	
F	F	BAN	Flag	
			Figure 3/Q.703	

English	French	Spanish	Meaning	
FAM	AD	MDA	Forward–address message	
			Table 3/Q.723	
FCM	CF	MCF	Signalling traffic flow control messages	
			Table 1/Q.704	
FDM	MRF	MDF	Frequency division multiplex	
			Recommendation Q.723, § 2.2.3, Recommendation Q.724, § 9	
FIB	BIA	BID	Forward indicator bit	
			Figures 3/Q.703, 13/Q.703, 15/Q.703	
FISU	TSR	USR	Fill–in signal unit	
			Figures 7/Q.703, 8/Q.703, 13–16/Q.703	
FOT	IOP	INT	Forward–transfer signal	
			Table 3/Q.723	
FSM	EA	MEL	Forward set–up message	
			Table 3/Q.723	
FSN	NSA	NSD	Forward sequence number	
			Figures 3/Q.703, 13/Q.703	
GRA	RZA	ARG	Circuit group reset–acknowledgement message	
			Table 3/Q.723	
GRM	SGC	MSG	Circuit group supervision message	
			Table 3/Q.723	
GRQ	DEG	MPG	General request message	
GRS	RZG	MRG	Circuit group reset message	
			Table 3/Q.723	
GSM	ING	MEG	General forward setup information message	
HBA	BHA	ABGSF	Hardware failure oriented group blocking–acknowledgement message	
			Table 3/Q.723	
HGB	BLH	BGSF	Hardware failure oriented group blocking message	
			Table 3/Q.723	
HGU	DBH	DGSF	Hardware failure oriented group unblocking message	
			Table 3/Q.723	
HUA	DHA	ADGSF	Hardware failure oriented group unblocking acknowledgement message	
			Table 3/Q.723	
HMDC	ODC	HDCM	Message discrimination	
			Recommendation Q.704, § 2, Figures 23–26/Q.704	
HMDT	ODT	HDTM	Message distribution	
			Recommendation Q.704, § 2, Figures 23–25/Q.704, 28/Q.704, 30/Q.704, 31/Q.704, 42/Q.704, 44–46/Q.704, 2/Q.707	
HMRT	OAC	HENM	Message routing	
			Recommendation Q.704, § 2, Figures 23/Q.704, 24/Q.704, 26/Q.704, 27/Q.704, 30/Q.704, 31/Q.704, 32/Q.704, 33/Q.704, 42/Q.704, 44/Q.704, 45/Q.704, 46/Q.704, 2/Q.707	

English	French	Spanish	Meaning	
HO	HO	EO	Heading code	
			Recommendation Q.704, § 15.3, Figure 16/Q.704, Recommendation Q.707, § 5.3, Figure 1/Q.707, Recommendation Q.723, §§ 3.1 and 3.2	
H1	H1	E1	Heading code	
			Recommendation Q.704, § 15.3, Figure 16/Q.704, Recommendation Q.723, § 3.1	
IAC	CAI	CAI	Initial alignment control	
			Figures 8/Q.703, 9/Q.703, 13–17/Q.703	
IAI	MIS	MIA	Initial address message with additional information	
			Table 3/Q.723	
IAM	MIA	MID	Initial address message	
			Table 3/Q.723, Figures 3/Q.724, 6/Q.724	
ISDN–UP	SSUR	PU–RDSI	ISDN User Part	
(ISUP)			Recommendations Q.700 and Q.761 to Q.764	
ISP	PSI	PSI	International signalling point	
			Recommendation Q.705, § 3, Figure 1/Q.705	
L1	N1	N1	Level 1	
			Figures 12/Q.703, 35/Q.704, 38–40/Q.704	
L2	N2	N2	Level 2	
			Figures 8/Q.703, 9/Q.703, 12/Q.703, 13/Q.703, 15/Q.703, 23/Q.704, 24/Q.704, 26/Q.704, 27/Q.704, 30/Q.704, 35/Q.704, 37/Q.704	
L3	N3	N3	Level 3	
			Figures 8/Q.703, 9/Q.704, 13/Q.703, 15/Q.703, 23/Q.704, 24/Q.704, 26/Q.704, 30/Q.704, 31/Q.704, 34/Q.704, 35/Q.704, 37/Q.704, 38/Q.704, 39/Q.704	
L4	N4	N4	Level 4	
			Figures 23/Q.704, 25–27/Q.704, 34/Q.704	
LI	INL	IL	Length indicator	
			Recommendation Q.703, § 2.2, Figure 3/Q.703	
LLSC	GCSF	CCE	Link set control	
			Figures 29/Q.704, 35–37/Q.704	
LOS	LHS	LFS	Line–out–of–service signal	
			Table 3/Q.723, Figure 3/Q.724	
LSAC	GCSA	CAE	Signalling link activity control	
			Recommendation Q.704, § 12.6, Figures 28–30/Q.704, 35‑41/Q.704	
LSC	SET	CEE	Link state control	
			Figures 7–10/Q.703, 13–18/Q.703, Recommendation Q.704, § 14.6, Figure 41/Q.704	
LSDA	GCAL	AED	Signalling data link allocation	
			Recommendation Q.704, § 12.6, Figures 35/Q.704, 37–40/Q.704, 42/Q.704	

English	French	Spanish	Meaning	
LSLA	GCAC	AES	Signalling link activation	
			Recommendation Q.704, § 12.6, Figures 35/Q.704, 37/Q.704, 38/Q.704, 41/Q.704, 42/Q.704	
LSLD	GCDA	DES	Signalling link deactivation	
			Recommendation Q.704, § 12.6, Figures 35/Q.704, 37/Q.704, 40/Q.704, 41/Q.704, 42/Q.704	
LSLR	GCRE	RES	Signalling link restoration	
			Recommendation Q.704, § 12.6, Figures 35/Q.704, 37/Q.704, 39/Q.704, 41/Q.704, 42/Q.704	
LSSU	TSE	UEE	Link status signal units	
			Figures 13–16/Q.703	
LSTA	GCAT	ATS	Signalling terminal allocation	
			Recommendation Q.704, § 12.6, Figures 35/Q.704, 38/Q.704, 39/Q.704, 40/Q.704, 41/Q.704	
MBA	BMA	ABGM	Maintenance oriented group–blocking–acknowledgement	
			Table 3/Q.723	
MGB	BLM	BGM	Maintenance oriented group blocking message	
			Table 3/Q.723	
MGMT	GES	SGE	Management system	
			Figures 8/Q.703, 27/Q.704, 28/Q.704, 35–37/Q.704, 2/Q.707	
MGU	DBM	DGM	Maintenance oriented group unblocking message	
			Table 3/Q.723	
MPR	INU	PIMM	Misdialled trunk prefix	
			Table 3/Q.723	
MSU	TSM	USM	Message signal unit	
			Recommendation Q.701, § 2.3, Figures 7/Q.703, 8/Q.703, 14/Q.703, 15/Q.703, 16/Q.703	
MTP	SSTM	PTM	Message transfer part	
			Recommendation Q.701, § 2.1, Recommendation Q.721, § 1	
MUA	DMA	ADGM	Maintenance oriented group unblocking–acknowledgement message	
			Table 3/Q.723	
NACK	ACN	RN	Negative acknowledgement	
			Figures 7/Q.703, 13/Q.703, 14/Q.703	
NNC	ERN	CRN	National–network–congestion signal	
			Table 3/Q.723, Figure 3/Q.724	
NSP	PSN	PSN	National signalling point	
			Recommendation Q.705, § 3, Figure 1/Q.705	
OMAP	SSEM	POMA	Operation, Administration and Maintenance Part	
			Recommendations Q.700 and Q.795	
OPC	CPO	CPO	Originating point code	
			Recommendation Q.704, §§ 2.2.3 and 13.2, Figures 3/Q.704 and 14/Q.704, Recommendation Q.706, § 3, Recommendation Q.723, § 2.2.1	

English	French	Spanish	Meaning	
PCM	MIC	MIC	Pulse code modulation	
			Recommendation Q.702, § 5.3	
PCR	RCP	RCP	Preventive cyclic retransmission	
			Tables 1/Q.706, 2/Q.706	
POC	SIP	CIP	Processor outage control	
			Figures 8/Q.703, 10/Q.703	
RAN	NRP	RRE	Reanswer signal	
			Table 3/Q.723, Figure 3/Q.724	
RC	REC	CR	Reception control	
			Figures 8/Q.703, 9/Q.703, 11/Q.703, 13–16/Q.703	
RLG	LIG	LGU	Release–guard signal	
			Table 3/Q.723, Figures 2/Q.724, 3/Q.724, 6/Q.724, 7/Q.724	
RSC	RZC	RCI	Reseat–circuit signal	
			Table 3/Q.723	
RSM	TR	MPR	Signalling–route–set–test message	
			Table 1/Q.704	
RSRT	GRTF	CPC	Signalling route set test control	
			Recommendation Q.704, § 13.5, Figures 23/Q.704, 29/Q.704, 43‑46/Q.704	
RST	TRS	PRS	Signalling–route–set–test signal	
			Table 1/Q.704	
RTAC	GRTA	CTA	Transfer allowed control	
			Recommendation Q.704, § 13.3, Figures 29/Q.704, 33/Q.704, 37/Q.704, 43/Q.704, 45/Q.704, 46/Q.704	
RTB	TRT	MTR	Retransmission buffer	
			Figures 7/Q.703, 13/Q.703, 15/Q.703	
RTPC	GRTI	CTP	Transfer prohibited control	
			Recommendation Q.704, § 13.2, Figures 26/Q.704, 29/Q.704, 32/Q.704, 43/Q.704, 44/Q.704, 46/Q.704	
SAM	MSA	MSD	Subsequent–address message	
			Table 3/Q.723, Figure 3/Q.724	
SAO	MSS	SDU	Subsequent–address message with one signal	
			Table 3/Q.723	
SBA	BSA	ABGSL	Software generated group blocking–acknowledgement message	
			Table 3/Q.723	
SBM	SE	MEC	Successful–backward–set–up information message	
			Table 3/Q.723	
SCCP	SSCS	PCCS	Signalling Connection Control Part	
			Recommendations Q.700, Q.711–Q.714 and Q.716	
SDL	LDS	LED	Functional specification and description language	
			Recommendations Q.703, § 12, Q.704, § 6, Q.707, Recommendations Q.714, Q.724, Q.764, Q.774	

English	French	Spanish	Meaning	
SEC	EEC	CEC	Switching–equipment–congestion signal	
			Table 3/Q.723, Figure 3/Q.724	
SF	ETC	CE	Status field	
			Figure 3/Q.703	
SGB	BLS	BGSL	Software generated group blocking message	
			Recommendation Q.723, Table 3/Q.723	
SGU	DBS	DGSL	Software generated group unblocking message	
			Recommendation Q.723, Table 3/Q.723	
SI	INS	IS	Service indicator	
			Recommendation Q.704, § 14	
SIE	ETAU	IAE	Status indication “emergency terminal status”	
			Recommendation Q.703, §§ 7.2, 7.3 and 10.1.3, Figures 2/Q.703, 4/Q.703, 7–9/Q.703, 13–16/Q.703	
SIF	INF	CIS	Signal information field	
			Figure 3/Q.703	
SIN	ETAN	IAN	Status indication “normal terminal status”	
			Recommendation Q.703, §§ 7.2, 7.3 and 10.1.3, Figures 2/Q.703, 4/Q.703, 7–9/Q.703, 13–16/Q.703	
SIO	SER	OIS	Service information octet	
			Figure 3/Q.703, Recommendation Q.723, § 1.2	
SIO2)	ETAP	IFA	Status indication “out of alignment”	
			Recommendation Q.703, §§ 7.2, 7.3 and 10.1.3, Figures 2/Q.703, 4/Q.703, 7–9/Q.703, 13–16/Q.703	
SIOS	ETHS	IFS	Status indication “out of service”	
			Recommendation Q.703, §§ 7.2, 7.3 and 10.1.3, Figures 2/Q.703, 4/Q.703, 7–9/Q.703, 13–16/Q.703	
SIPO	ETIP	IIP	Status indication “processor outage”	
			Recommendation Q.703, § 10.1.3, Figures 2/Q.703, 7/Q.703, 8/Q.703, 13–16/Q.703	
SLC	COC	CES	Signalling link code	
			Recommendation Q.704, § 15, Figure 14/Q.704	
SLM	GCS	GES	Signalling link management	
			Recommendation Q.704, §§ 12.1 and 12.6, Figures 23/Q.704, 25/Q.704, 26/Q.704, 27/Q.704, 29/Q.703	
SLS	SCS	SES	Signalling link selection code	
			Recommendation Q.704, § 2.2.4, Figures 3/Q.704, 4/Q.704, 26/Q.704, A–3.1/Q.705	
SLTA	ESCA	AMPS	Signalling link test message acknowledgement	
SLTM	ESCO	MPES	Signalling link test message	
			Figure 2/Q.707	

English	French	Spanish	Meaning	
SMH	OMS	TMS	Signalling message handling	
			Recommendation Q.704, § 2, Figures 23/Q.704, 43/Q.704	
SP	PS	PS	Signalling point	
			Figures 8/Q.704, 23/Q.704, 24/Q.704, 26/Q.704, 27/Q.704, 30/Q.704, 31/Q.704, 42–44/Q.704	
SPRC	CPS	CPS	Signalling procedure control	
			Recommendation Q.724, § 10.1, Figures 1–7/Q.724	
SRM	GRS	GRS	Signalling route management	
			Recommendation Q.704, § 13, Figures 23/Q.704, 25–27/Q.704, 43/Q.704	
SSB	OCC	ABO	Subscriber–busy signal (electrical)	
			Table 3/Q.723, Figure 3/Q.724	
SSF	DSS	CSS	Sub–service field	
			Recommendation Q.704, § 13.1.1, Recommendation Q.723, § 1.2	
SST	TSI	TIE	Send–special–information–tone signal	
			Figures 1–7/Q.724	
ST	ST	SFN	End–of–pulsing signal	
			Recommendation Q.724, § 1.3	
STLC	ESC	CPES	Signalling link test control	
			Figures 25/Q.704, 26/Q.704, 2/Q.707	
STM	GTS	GTS	Signalling traffic management	
			Recommendation Q.704, § 4, Figures 23/Q.704, 25–27/Q.704, 30/Q.704, 35/Q.704, 39/Q.704, 43/Q.704	
STP	PTS	PTS	Signalling transfer point	
			Figure 4/Q.701, Recommendation Q.705, § 3, Figures A–1/Q.705, A–2/Q.705, Recommendation Q.706, § 4.3.3, Table 3/Q.706	
SU	TS	US	Signal unit	
			Figures 2/Q.703, 7/Q.703	
SUA	DSA	ADGSL	Software generated group unblocking–acknowledgement messages	
			Table 3/Q.723	
SUERM	STTS	MUS	Signal unit error rate monitor	
			Figures 7/Q.703, 8/Q.703, 11/Q.703, 18/Q.703	
SUM	SEE	ESNC	Sample unsuccessful backward setup information message	
			Recommendation Q.723, § 3.7.1	
TB	TEM	MT	Transmission buffer	
			Figures 7/Q.703, 13/Q.703, 15/Q.703	
TC	GT	CT	Transaction Capabilities	
			Recommendations Q.700 and Q.771–Q.775	
TCAP	SSGT	PACT	Transaction Capabilities Application Part	
			Recommendations Q.700 and Q.771–Q.775.	
TCBC	GTCN	TCRS	Changeback control	
			Recommendation Q.704, § 6, Figures 27–29/Q.704, 31/Q.704	

English	French	Spanish	Meaning	
TCOC	GTCS	TCER	Changeover control	
			Recommendation Q.704, § 5, Figures 27–30/Q.704, 37/Q.704	
TCRC	GTRN	TCRC	Controlled rerouting control	
			Recommendation Q.704, § 8, Figures 27/Q.704, 29/Q.704, 33/Q.704, 45/Q.704	
TFA	TAO	TRA	Transfer–allowed signal	
			Table 1/Q.704	
TFM	TF	MTR	Transfer–prohibited and transfer–allowed messages	
			Table 1/Q.704	
TFP	TIO	PTR	Transfer–prohibited signal	
			Table 1/Q.704	
TFRC	GTRS	TCRF	Forced rerouting control	
			Recommendation Q.704, § 7, Figures 27/Q.704, 29/Q.704, 32/Q.704	
TLAC	GTSD	TCDE	Link availability control	
			Recommendation Q.704, Figures 27–31/Q.704, 37/Q.704	
TSFC	GTFX	CFTS	Signalling traffic flow control	
			Figures 27/Q.704, 29/Q.704, 34/Q.704	
TSRC	GTAC	CEN	Signalling routing control	
			Recommendation Q.704, Figures 27–34/Q.704, 36/Q.704, 37/Q.704, 44–46/Q.704	
TUP	SSUT	PUT	Telephone user part	
			Recommendation Q.701, § 2.1, Figure 2/Q.701, Recommendation Q.721, § 1	
TXC	EMI	CT	Transmission control	
			Figures 8/Q.703, 9/Q.703, 12–16/Q.703	
UBA	DBA	ARD	Unblocking–acknowledgement signal	
			Table 3/Q.723	
UBL	DBO	DBL	Unblocking signal	
			Table 3/Q.723	
UBM	EE	MEI	Unsuccessful–backward–set–up–information message	
			Table 3/Q.723	
UNN	NNU	NNA	Unallocated–national–number signal	
			Table 3/Q.723, Figure 3/Q.724	
UP	SSU	PU	User part	
			Figure 2/Q.704