Miscellaneous Abbreviations and Signals

Used over HF radio circuits to assist mobile communications, a few have been adopted by radio amateurs.

Miscellaneous Abbreviations and Signals
Abbreviation	Information
AA	All after... (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
AB	All before... (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
ADS	Address (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
AR	End of transmission.
AS	Waiting period.
BK	Signal used to interrupt a transmission in progress.
BN	All between... and... (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
BQ	A reply to an RQ.
BT	Signal to mark the separation between different parts of the same transmission.
C	Yes.
CFM	Confirm (or I confirm).
CL	I am closing my station.
COL	Collate (or I collate).
CORRECTION	Cancel my last word or group. The correct word or group follows (used in radiotelephony, spoken as KOR-REK-SHUN).
CP	General call to two or more specified stations.
CQ	General call to all stations.
CS	Call sign (used to request a call sign).
DE	From... (used to precede the name or other identification of the calling station).
DF	Your bearing at... hours was... degrees, in the doubtful sector of this station, with a possible error of... degrees.
DO	Bearing doubtful. Ask for another bearing later (or at... hours).
DSC	Digital selective calling.
E	East (cardinal point).
ETA	Estimated time of arrival.
INTERCO	International Code of Signals groups follow (used in radiotelephony, spoken as IN-TER-CO).
K	Invitation to transmit.
KA	Starting signal.
KTS	Nautical miles per hour (knots).
MIN	Minute (or Minutes).
MSG	Prefix indicating a message to or from the master of a ship concerning its operation or navigation.
MSI	Maritime safety information.
N	North (cardinal point).
NBDP	Narrow-band direct-printing telegraphy.
NIL	I have nothing to send to you.
NO	No (negative).
NW	Now.
NX	Notice to Mariners (or Notice to Mariners follows).
OK	We agree (or It is correct).
OL	Ocean letter.
P	Prefix indicating a private radiotelegram.
PBL	Preamble (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
PSE	Please.
R	Received.
RCC	Rescue coordination centre.
REF	Reference to ? (or Refer to ?).
RPT	Repeat (or I repeat) (or Repeat ?).
RQ	Indication of a request.
S	South (cardinal point).
SAR	Search and Rescue.
SIG	Signature (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
SLT	Radiomaritime Letter.
SVC	Prefix indicating a service telegram.
SYS	Refer to your service telegram.
TFC	Traffic.
TR	Used by a land station to request the position and next port of call of a mobile station; used also as a prefix to the reply.
TU	Thank you.
TXT	Text (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
VA	End of work.
W	West (cardinal point).
WA	Word after... (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
WB	Word before... (used after a question mark in radiotelegraphy or after RQ in radiotelephony (in case of language difficulties) or after RPT, to request a repetition).
WD	Word(s) or Group(s).
WX	Weather report (or Weather report follows).
XQ	Prefix used to indicate the transmission of a service note.
YZ	The words which follow are in plain language.

So now you know. Good to see a list with such a long history also reflects the latest technology.