The ARRL Handbook used to give a whole list of all these prosigns, both the ones that are sent as one character and those that are individual characters. I'm not sure they do that anymore. And no one really cares as we are getting further and further away from any kind of "standard operating procedures."
I care - so here's my list. In this list, underlining means sent as one character:
Prosigns:
AR End of transmission
K Go ahead
KN Go ahead, specific station, all others keep out
SK End of QSO
CL Closing down station, will not listen for calls.
DE From, this is
CQ Call to any station
Abbrevations:
AA All after
AB All before
ABT About
ADR Address
AGN Again
AMP Amplifier, ampere
ANT Antenna
BCI Broadcast Interference
BCNU Be seeing you
BK Break, back
BN Between
B4 Before
C Yes
CFM Confirm
CK Check
CL Call
CLD Called
CLG Calling
CU See you
CUD Could
CUL See you later
CUM Come
DLVD Delivered
DX Distance
ES &, and
FB Fine business, excellent
GA Go ahead, good afternoon
GB Goodbye, God bless
GBA Give better address
GE Good evening
GG Going
GM Good morning
GN Good night
GND Ground
GUD Good
HAW Laughing
HI Laughing
HNDL Handle
HR Here, hear
HV Have
HW How
LID Poor/unskilled/inconsiderate operator
MILL Typewriter
MILS Milliamperes
MSG Message
N No
ND Nothing doing
NIL Nothing
NR Number
NW Now
OB Old boy
OM Old man
OP Operator, name of operator
OSC Oscillator
OT Old Timer
PSE Please
PWR Power
R Received, are
RPT Repeat
RX Receiver
SED Said
SEZ Says
SIG Signature
SINE Operator's initials or nickname
SK Silent Key
SKED Schedule
SRI Sorry
SVC Service
TFC Traffic
TNW Tomorrow
TNX Thanks
TT That
TU Thank you
TVI Television Interference
TX Transmitter
TXT Text
UR Your, you're
URS Yours
VY Very
WA Word after
WB Word before
WD Word, wood
WKD Worked
WUD Would
WX Weather
XCVR Transceiver
XTAL Crystal
XYL Wife
YL Young lady
73 Best regards
88 Love & kisses
Those are just the common ones, there are many more.
73 de Jim, N2EY