Prosigns (W2LJ)

There seems to be a lot of confusion out there amongst CW operators (newer ones, especially)
about the proper use of prosigns in a CW QSO.  Here's a table of the most common prosigns
and their proper use:

Prosign Answer or Advice Example
BT
A pause or a seperator
NAME HR IS LARRY
BT QTH IS .....
AR
Used at end of transmission when you are sending it back to the other station.  Also used at the end when you
answer a CQ.
BTU BOB AR
W3BBO DE W2LJ KN

W3BBO W3BBO DE
W2LJ W2LJ W2LJ AR

SK
Pretty much the same as AR; but to be
used only at the END of your last transmission of a QSO.
TNX QSO BOB BT 73
ES GN SK W3BBO
DE W2LJ K
BK
Used as a break in a transmission, when you expect the other station to reply quickly without going through station ID.
(W3BBO sends)
WHAT RIG U USING?
BK
(W2LJ replies)
RIG HR IS K2
K
Go ahead .... over.  Use this when you are turning it over to another station. You also use this at the of a CQ.  Do NOT use at the end when you answer a CQ; because you're not sure the CQing station will be coming back to you.
HOW CPY NOW BOB?
AR W3BBO DE
W2LJ K
KN
Almost the same as K; but used only when you want a specific station AND NO ONE ELSE to come back to you. This can be useful when your in a multi-op roundtable QSO.

W3BBO DE W2LJ
KN

CL
Use this only when you intend this to be your last QSO and you will be turning off your equipment. A good way to let other ops know that you will not respond to any further calls.
NICE QSO BOB BT
73 ES GN CUL
SK W3BBO DE
W2LJ CL
 

Other popular abbreviations used in radiotelegraphy

AA All after (used after question mark to request a repetition)
AB All before (similarly)
ARRL American Radio Relay League
ABT About
ADR Address
AGN Again
ANT Antenna
ARND Around
BCI Broadcast interference
BK Break (to pause transmission of a message, say)
BN All between
BTR Better
BUG Semiautomatic mechanical key
B4 Before
C Yes; correct
CBA Callbook address
CFM Confirm
CK Check
CL Clear (I am closing my station)
CLG Calling
CQ Calling any station
CQD Original International Distress Call
CS Callsign
CTL Control
CUD Could
CUL See you later
CUZ Because
CW Continuous wave (i.e., radiotelgraph)
CX Conditions
DE From (or "this is")
DN Down
DR Dear
DSW Goodbye (Russian: до свидания [Do svidanya])
DX Distance (sometimes refers to long distance contact), foreign countries
EMRG Emergency
ENUF Enough
ES And
FB Fine business (Analogous to "OK")
FCC Federal Communications Commission
FER For
FM From
FREQ Frequency
FWD Forward
GA Good afternoon or Go ahead (depending on context)
GE Good evening
GG Going
GM Good morning
GN Good night
GND Ground (ground potential)
GUD Good
GX Ground
HI Laughter
HR Here, hear
HV Have
HW How
II I say again
IMP Impedance
KN Over
LID Poor operator
MILS Milliamperes
MNI Many
MSG Message
N No; nine
NIL Nothing
NR Number
NW Now
NX Noise; noisy
OB Old boy
OC Old chap
OM Old man (any male amateur radio operator is an OM)
OO Official observer
OP Operator
OT Old timer
OTC Old timers club
OOTC Old old timers club
PSE Please
PWR Power
PX Prefix
QCWA Quarter Century Wireless Association
R Are; received as transmitted (origin of "Roger"), or decimal point (depending on context)
RCVR Receiver (radio)
RFI Radio Frequency Interference
RIG Radio apparatus
RPT Repeat or report (depending on context)
RPRT Report
RST Signal report format (Readability-Signal Strength-Tone)
RTTY Radioteletype
RX Receiver
SAE Self-addressed envelope
SASE Self-addressed, stamped envelope
SED Said
SEZ Says
SFR So far (proword)
SIG Signal or signature
SIGS Signals
SK Out (proword)
SKED Schedule
SMS Short message service
SN Soon
SNR Signal-to-noise ratio
SRI Sorry
SSB Single sideband
STN Station
T Zero
TEMP Temperature
TFC Traffic
TKS Thanks
TMW Tomorrow
TNX Thanks
TT That
TU Thank you
TVI Television interference
TX Transmit, transmitter
TXT Text
U You
UR Your or You're (depending on context)
URS Yours
VX Voice; phone
VY Very
W Watts
WA Word after
WB Word before
WC Wilco
WDS Words
WID With
WKD Worked
WKG Working
WL Will
WUD Would
WTC Whats the craic? (Irish Language: [Conas atá tú?])
WX Weather
XCVR Transceiver
XMTR Transmitter
XYL Wife
YF Wife
YL Young lady (used for any female)
ZX Zero beat
73 Best regards
88 Love and kisses