Ham Radio Q-signs

Q-signs, or Q-signals, or Q-codes are Morse code abbreviations of frequent transmission-related information. They arose informally, I guess, but at this point knowledge of some of the more common ones is an established part of HAM licensing exams -- the ``no-code'' parts of the tests, yet (so the more common Q-signs should be known even by those who are licensed without Morse code proficiency). [No-code licenses have been issued by the FCC since the 80's, no-code technician class licenses since 1991.]

Although ``Q'' stands for Query or Question, most signs function in both declarative and interrogative mood, depending on whether or not the sign is followed by a question mark. Also, some implicit identity information (sender or receiver, or a third party, if one is indicated) is dictated by the common sense [specifically, an understanding of what the sender of the Q-sign would know or want to know]. Thus, for example,
QRH means `your frequency varies,'
while
QRH? means `does my frequency vary?'

Sign Meaning
QRA Name (or grid square) of station
QRB Distance between us [in km].
QRG Exact frequency [mine or yours or that of ...]
QRH Frequency varies
QRI Tone of transmission
[1 = good, 2 = variable, 3 = bad]
QRJ Signal weak
QRK Intelligibility of signal
[1 = bad, 2 = poor, 3 = fair, 4 = good, 5 = excellent]
QRL Listen (i.e., ``Shaddup! I am busy [with ...].'' or ``Are you busy? Can we talk?'')
QRM Interference in signal
[1 = nil, 2 = slight, 3 = moderate, 4 = severe, 5 = extreme]
QRN Noise (``static'') in signal
[1 = nil, 2 = slight, 3 = moderate, 4 = severe, 5 = extreme]
QRO Increase power
QRP Decrease power or low power
QRQ Send faster [... WPM]
QRS Send more slowly [... WPM]
QRT Stop sending
QRU Listening for messages directed to station
QRV Ready
QRX Next call [at ... hours [on ... kHz]]
CB usage: Wait [...minutes]
QRZ Call sign
CB usage: Handle
QSA 1-5 Signal strength
[1 = Scarcely perceptible, 2 = Weak, 3 = Fairly good, 4 = Good, 5 = Very good]
QSB Signal fading
QSL Receipt acknowledgment
QSO Can communicate with ... { directly | by relay through ... }
QSP Relay to ...
QSX Listening to ( call / sign[s] ) on ... kHz
QSY Change frequency to ... kHz
CB usage: Change [to ...] channel
QSZ Send each word or group twice [or ... times]
QTC Have messages.
QTH Geographic location
CB usage: Home station
QTR Current time
QUM Resume normal working

For another file of Q-signs used in CW, look here.