Q code

"QRO" redirects here. For the airport in Mexico, see Querétaro International Airport. For the 2-dimensional barcode standard, see QR code.

The Q code is a standardized collection of three-letter codes all of which start with the letter "Q". It is an operating signal initially developed for commercial radiotelegraph communication and later adopted by other radio services, especially amateur radio. To distinguish the use of "Q" codes transmitted as questions from those transmitted as statements, operators used the Morse question "INT" (dit dit...dah dit...dah) as a prefix to the "Q" code.

Although Q codes were created when radio used Morse code exclusively, they continued to be employed after the introduction of voice transmissions. To avoid confusion, transmitter call signs are restricted; no country is ever issued an ITU prefix starting with "Q".

Codes in the range QAA–QNZ are reserved for aeronautical use; QOA–QQZ for maritime use and QRA–QUZ for all services.

"Q" has no official meaning, but it is sometimes assigned with a word with mnemonic value, such as "Queen's" (e.g. QFE = Queen's Field Elevation), "Query", "Question", or "reQuest".

Early developments

The original Q codes were created, circa 1909, by the British government as a "list of abbreviations... prepared for the use of British ships and coast stations licensed by the Postmaster General". The Q codes facilitated communication between maritime radio operators speaking different languages, so they were soon adopted internationally. A total of forty-five Q codes appeared in the "List of Abbreviations to be used in Radio Communications", which was included in the Service Regulations affixed to the Third International Radiotelegraph Convention in London (The Convention was signed on July 5, 1912, and became effective July 1, 1913.)

The following table reviews a sample of the all-services Q codes adopted by the 1912 Convention:

First Twelve Q Codes Listed in the 1912 International Radiotelegraph Convention Regulations

Code	Question	Answer or Notice
QRA	What ship or coast station is that?	This is ____.
QRB	What is your distance?	My distance is ____.
QRC	What is your true bearing?	My true bearing is ____ degrees.
QRD	Where are you bound for?	I am bound for ____.
QRF	Where are you bound from?	I am bound from ____.
QRG	What line do you belong to?	I belong to the ____ Line.
QRH	What is your wavelength in meters?	My wavelength is ____ meters.
QRJ	How many words have you to send?	I have ____ words to send.
QRK	How do you receive me?	I am receiving (1–5). 1 is unreadable and 5 is perfect.
QRL	Are you busy?	I am busy.
QRM	Are you being interfered with?	I am being interfered with.
QRN	Are the atmospherics strong?	Atmospherics (noise) are very strong.

Later usage

Over the years the original Q codes were modified to reflect changes in radio practice. For example, QSW/QSX originally stood for, "Shall I increase/decrease my spark frequency?", but in the 1920s, spark-gap transmitters were banned in the United States, rendering that meaning obsolete. By the 1970s, the Post Office Handbook for Radio Operators listed over a hundred Q codes, covering a wide range of subjects including radio procedures, meteorology, radio direction finding, and search and rescue.

Some Q codes are also used in aviation, in particular QNE, QNH and QFE, referring to certain altimeter settings. These codes are used in radiotelephone conversations with air traffic control as unambiguous shorthand, where safety and efficiency are of vital importance. A subset of Q codes is used by the Miami-Dade County, Florida local government for law enforcement and fire rescue communications, one of the few instances where Q codes are used in ground voice communication.

The QAA–QNZ code range includes phrases applicable primarily to the aeronautical service, as defined by the International Civil Aviation Organisation. The QOA–QQZ code range is reserved for the maritime service. The QRA–QUZ code range includes phrases applicable to all services and is allocated to the International Telecommunications Union. QVA–QZZ are not allocated. Many codes have no immediate applicability outside one individual service, such as maritime operation (many QO or QU series codes) or radioteletype operation (the QJ series).

Many military and other organizations that use Morse code have adopted additional codes, including the Z code used by most European and NATO countries. The Z code adds commands and questions adapted for military radio transmissions, for example, "ZBW 2", which means "change to backup frequency number 2", and "ZNB abc", which means "my checksum is abc, what is yours?"

Used in their formal "question/answer" sense, the meaning of a Q code varies depending on whether the individual Q code is sent as a question or an answer. For example, the message "QRP?" means "Shall I decrease transmitter power?", and a reply of "QRP" means "Yes, decrease your transmitter power", whereas an unprompted statement "QRP" means "Please decrease your transmitter power". This structured use of Q codes is fairly rare and now mainly limited to amateur radio and military Morse code (CW) traffic networks.

Breakdown by service

• QAA to QNZ – Assigned by the International Civil Aviation Organization (ICAO).
• QOA to QQZ – For the Maritime Mobile Service.
• QRA to QUZ – Assigned by the International Telecommunications Union Radiocommunication Sector (ITU-R).
• QN- - The American Radio Relay League (ARRL) has also developed its own codes for message handling located in this range. Even though they overlap with other signals, the ARRL determined that their exclusive use in NTS nets limits confusion.

Aeronautical Code signals (QAA–QNZ; ICAO)

Main article: Aeronautical Code signals

First defined in ICAO publication "Doc 6100-COM/504/1" and in "ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PANS-ABC)" [Doc8400-4] (4th edition 1989), the majority of the Q codes have slipped out of common use; for example today reports such as QAU ("I am about to jettison fuel") and QAZ ("I am flying in a storm") would be voice or computerized transmissions. But several remain part of the standard ICAO radiotelephony phraseology in aviation. These are also part of ACP131, which lists all ITU-R Q Codes, without grouping them by aeronautical/marine/general use.

	Question ?	Answer or Advice
QAB	May I have clearance (for ...) from ... (place) to ... (place) at flight level/altitude ... ?	You are cleared (or ... is cleared) by ... from ... (place) to ... (place) at flight level/altitude ...
QAF	Will you advise me when you are (were) at (over) ... (place)?	I am (was) at (over) ... (place) (at ... hours) at flight level/altitude ...
QAG		Arrange your flight in order to arrive over ... (place) at ... hours. or I am arranging my flight in order to arrive over ... (place) at ... hours.
QAH	What is your height above ... (datum)?	I am at .... flight level/altitude ... or Arrange your flight so as to reach flight level/altitude ... at ... (hours or place).
QAI	What is the essential traffic respecting my aircraft?	The essential traffic respecting your aircraft is ...
QAK	Is there any risk of collision?	There is risk of collision.
QAL	Are you going to land at ... (place)? or Has aircraft ... landed at ... (place)?	I am going to land at ... (place). or (You may) land at ... (place). or Aircraft ... landed at ... (place).
QAM	What is the latest available meteorological observation for ... (place)?	Meteorological observation made at ... (place) at ... hours was as follows ... Note.- The information may be given in Q Code form or the METAR form.
QAN	What is the surface wind direction and speed at ... (place)?	The surface wind direction and speed at ... (place) at ... hours is ... (direction) ... (speed).
QAO	What is the wind direction in degrees TRUE and speed at ... (position or zone/s) at each of the ... (figures) ... (units) levels above ... (datum)?	The wind direction and speed at (position or zone/s) at flight level/altitude ... is: ... (vertical distance) ... degrees TRUE ... (speed).
QAP	Shall I listen for you (or for ...) on ... kHz (... MHz)?	Listen for me (or for ...) on ... kHz (... MHz).
QAQ	Am I near a prohibited, restricted or danger area? or Am I near area ... (identification of area)?	You are ... 1) near 2) flying within area ... (identification of area).
QAR	May I stop listening on the watch frequency for ... minutes?	You may stop listening on the watch frequency for ... minutes.
QAU	Where may I jettison fuel?	I am about to jettison fuel. or Jettison fuel in ... (area).
QAW		I am about to carry out overshoot procedure.
QAY	Will you advise me when you pass (passed) ... (place) bearing 090 (270) degrees relative to your heading?	I passed ... (place) bearing ... degrees relative to my heading at ... hours.
QAZ	Are you experiencing communication difficulties through flying in a storm?	I am experiencing communication difficulties through flying in a storm.
QBA	What is the horizontal visibility at ... (place)?	The horizontal visibility at ... (place) at ... hours is ... (distance figures and units).
QBB	What is the amount, type and height above official aerodrome elevation of the base of the cloud [at ... (place)]?	The amount, type and height above official aerodrome elevation of the base of the cloud at ... (place) at ... hours is: ... eights (... type) at ... (figures and units) height above official aerodrome elevation.
QBC	Report meteorological conditions as observed from your aircraft [at ... (position or zone)] [(at ... hours)].	The meteorological conditions as observed from my aircraft at ... (position or zone) at ... hours at ... (figures and units) height above ... (datum) are ... Note.-The answer is required in the format of an AIREP message.
QBD	How much fuel have you remaining (expressed as hours and/or minutes of consumption)?	My fuel endurance is ... (hours and/or minutes).
QBE		I am about to wind in my aerial.
QBF	Are you flying in cloud?	I am flying in cloud at ... flight level/altitude ... [and I am ascending (descending) to flight level/altitude ...].
QBG	Are you flying above cloud?	I am flying above cloud and at flight level/altitude ... or Maintain a vertical distance of ... (figures and units) above clouds, smoke, haze or fog levels.
QBH	Are you flying below cloud?	I am flying below cloud and at flight level/altitude ... or Maintain a vertical distance of ... (figures and units) below cloud.
QBI	Is flight under IFR compulsory at ... (place) [or from ... to ... (place)]?	Flight under IFR is compulsory at ... (place) [or from ... to ... (place)].
QBJ	What is the amount, type and height above ... (datum) of the top of the cloud [at ... (position or zone)]?	At ... hours at ... (position or zone) the top of the cloud is: amount ... eights (... type) at ... (figures and units) height above ... (datum).
QBK	Are you flying with no cloud in your vicinity?	I am flying with no cloud in my vicinity and at flight level/altitude ...
QBM	Has ... sent any messages for me?	Here is the message sent by ... at ... hours.
QBN	Are you flying between two layers of cloud?	I am flying between two layers of cloud and at flight level/altitude ...
QBO	What is the nearest aerodrome at which flight under VFR is permissible and which would be suitable for my landing?	Flying under VFR is permissible at ... (place) which would be suitable for your landing.
QBP	Are you flying in and out of cloud?	I am flying in and out of cloud and at flight level/altitude ...
QBS		Ascend (or descend) to ... (figures and units) height above ... (datum) before encountering instrument meteorological conditions or if visibility falls below ... (distance figures and units) and advise.
QBT	What is the runway visual range at ... (place)?	The runway visual range at ... (place) at ... hours is ... (distance figures and units).
QBV	Have you reached flight level/altitude ... [or ... (area or place)]?	I have reached ... flight level/altitude ... [or ... (area or place)]. or Report reaching flight level/altitude ... [or ... (area or place)].
QBX	Have you left ... flight level/altitude ... [or ... (area or place)]?	I have left ... flight level/altitude ... [or ... (area or place)]. or Report leaving flight level/altitude ... [or ... (area or place)].
QBZ	Report your flying conditions in relation to clouds.	The reply to QBZ ? is given by the appropriate answer form of signals QBF, QBG, QBH, QBK, QBN and QBP.
QCA	May I change my flight level/altitude from ... to ... ?	You may change your flight level/altitude from ... to ... or I am changing my flight level/altitude from ... to ...
QCB		Delay is being caused by ... 1) your transmitting out of turn. 2) your slowness in answering. 3) lack of your reply to my ...
QCE	When may I expect approach clearance?	Expect approach clearance at ... hours. or No delay expected.
QCF		Delay indefinite. Expect approach clearance not later than ... hours.
QCH	May I taxi to ... (place)?	Cleared to taxi to ... (place).
QCI		Make a 360-degree turn immediately (turning to the ...). or I am making a 360-degree turn immediately (turning to the ...).
QCS		My reception on ... frequency has broken down.
QCX	What is your full call sign?	My full call sign is ... or Use your full call sign until further notice.
QCY		I am working on a trailing aerial. or Work on a trailing aerial.
QDB	Have you sent message ... to ... ?	I have sent message ... to ...
QDF	What is your D-Value at ... (position)? or What is the D-Value at ... (place or position) (at ... hours) for the ... millibar level?	My D-Value at ... (position) at ... (figures and units) height above the 1013.2 millibars datum is ... (D-Value figures and units) ... (specify plus or minus). or The D-Value at ... (place or position) at ... hours for the ... millibar level is (D-Value figures and units) ... (specify plus or minus). Note.- When the true altitude (radio altitude) is greater than the pressure altitude PS (Plus) is used and when it is less MS (Minus) is used.
QDL	Do you intend to ask me for a series of bearings?	I intend to ask you for a series of bearings.
QDM	Will you indicate the MAGNETIC heading for me to steer towards you (or ...) with no wind?	The MAGNETIC heading for you to steer to reach me (or ...) with no wind was ... degrees (at ... hours).
QDP	Will you accept control (or responsibility) of (for) ... now (or at ... hours)?	I will accept control (or responsibility) of (for) ... now (or at ... hours).
QDR	What is my MAGNETIC bearing from you (or from ...)?	Your MAGNETIC bearing from me (or from ...) was ... degrees (at ... hours).
QDT	Are you flying in visual meteorological condition?	I am flying in visual meteorological condition. or You are cleared subject to maintaining own separation and visual meteorological conditions.
QDU		Cancelling my IFR flight. or IFR flight cancelled at ... (time).
QDV	Are you flying in a flight visibility of less than ... (figures and units)?	I am flying in a flight visibility of less than ... (figures and units) at flight level/altitude ...
QEA	May I cross the runway ahead of me?	You may cross the runway ahead of you.
QEB	May I turn at the intersection?	Taxi as follows at the intersection ... (straight ahead DRT turn left LEFT turn right RITE).
QEC	May I make a 180-degree turn and return down the runway?	You may make a 180-degree turn and return down the runway.
QED	Shall I follow the pilot vehicle?	Follow the pilot vehicle.
QEF	Have I reached my parking area? or Have you reached your parking area?	You have reached your parking area. or I have reached my parking area.
QEG	May I leave the parking area? or Have you left the parking area?	You may leave the parking area. or I have left the parking area.
QEH	May I move to the holding position for runway number ... ? or Have you moved to the holding position for runway number ... ?	Cleared to the holding position for runway number ... or I have moved to the holding position for runway number ...
QEJ	May I assume position for take-off? or Have you assumed position for take-off?	Cleared to hold at take-off position for runway number ... or I am assuming take-off position for runway number ... and am holding.
QEK	Are you ready for immediate take-off?	I am ready for immediate take-off.
QEL	May I take-off (and make a ... hand turn after take-off)?	You are cleared to take-off (turn as follows after take-off ...).
QEM	What is the condition of the landing surface at ... (place)?	The condition of the landing surface at ... (place) is ... Note.- The information is given by sending appropriate NOTAM Code groups.
QEN	Shall I hold my position?	Hold your position
QEO	Shall I clear the runway (or landing area)? or Have you cleared the runway (or landing area)?	Clear the runway (or landing area). or I have cleared the runway (or landing area).
QES	Is a right-hand circuit in force at ... (place)?	A right-hand circuit is in force at ... (place).
QFA	What is the meteorological forecast for ... (flight, route, section of route or zone) for the period ... hours until ... hours?	The meteorological forecast for ... (flight, route, section of route or zone) for the period ... hours until ... hours is ...
QFB		The ... 1) approach 2) runway 3) approach and runway lights are out of order.
QFC	What is the amount, the type and the height above ... (datum) of the base of the cloud at ... (place, position or zone)?	At ... (place, position or zone) the base of the cloud is ... eighths ... type at ... (figures and units) height above ... (datum).
QFD	1) Is the ... visual beacon [at ... (place)] in operation? 2) Will you switch on the ... visual beacon [at ... (place)]? 3) Will you extinguish the aerodrome visual beacon [at ... (place)] until I have landed?	1) The ... visual beacon [at ... (place)] is in operation 2) I will extinguish the aerodrome visual beacon [at ... (place)] until your landing is completed.
QFE	What should I set on the subscale of my altimeter so that the instrument would indicate its height above the reference elevation being used?	If you set the subscale of your altimeter to read ... millibars, the instrument would indicate its height above aerodrome elevation (above threshold, runway number ...).
QFF	[At ... (place)] what is the present atmospheric pressure converted to mean sea level in accordance with meteorological practice?	At ... (place) the atmospheric pressure converted to mean sea level in accordance with meteorological practice is (or was determined at ... hours to be) ... millibars.
QFG	Am I overhead?	You are overhead.
QFH	May I descend below the clouds?	You may descend below the clouds.
QFI	Are the aerodrome lights lit?	The aerodrome lights are lit. or Please light the aerodrome lights.
QFL	Will you send up pyrotechnical lights?	I will send up pyrotechnical lights.
QFM	What flight level/altitude ... 1) should I maintain? 2) are you maintaining? 3) do you intend cruising at?	... 1) Maintain (or fly at) flight level/altitude ... 2) I am maintaining flight level/altitude ... 3) I intend cruising at flight level/altitude ...
QFO	May I land immediately?	You may land immediately.
QFP	Will you give me the latest information concerning ... facility [at ... (place)]?	The latest information concerning ... facility [at ... (place)] is as follows ... Note.- The information is given by sending appropriate NOTAM Code groups.
QFQ	Are the approach and runway lights lit?	The approach and runway lights are lit. or Please light the approach and runway lights.
QFR	Does my landing gear appear damaged?	Your landing gear appears damaged.
QFS	Is the radio facility at ... (place) in operation?	The radio facility at ... (place) is in operation (or will be in operation in ... hours). or Please have the ... radio facility at ... (place) put in operation.
QFT	Between what heights above ... (datum) has ice formation been observed [at ... (position or zone)]?	Ice formation has been observed at ... (position or zone) in the type of ... and with an accretion rate of ... between ... (figures and units) and ... (figures and units) heights above ... (datum).
QFU	What is the magnetic direction (or number) of the runway to be used?	The magnetic direction (or number) of the runway to be used is ... Note.- The runway number is indicated by a two-figure group and the magnetic direction by a three-figure group.
QFV	Are the floodlights switched on?	The floodlights are switched on. or Please switch on the floodlights.
QFW	What is the length of the runway in use in ... (units)?	The length of runway ... now in use is ... (figures and units).
QFX		I am working (or am going to work) on a fixed aerial. or Work on a fixed aerial.
QFY	Please report the present meteorological landing conditions [at ... (place)].	The present meteorological landing conditions at ... (place) are ... Note.- When given in Q Code the information is sent in the following sequence: QAN, QBA, QNY, QBB, QNH and/or QFE and, if necessary, QMU, QNT, QBJ.
QFZ	What is the aerodrome meteorological forecast for ... (place) for the period ... hours until ... hours?	The aerodrome meteorological forecast for ... (place) for the period ... hours until ... hours is ... Note.- When given in Q Code the following sequence of Q signal answer (or advice) forms is to be used: QAN, QBA, QNY, QBB and, if necessary, QMU, QNT and QBJ.
QGC		There are obstructions to the ... of ... runway ...
QGD	Are there on my track any obstructions whose elevation equals or exceeds my altitude?	There are obstructions on your track ... (figures and units) height above ... (datum).
QGE	What is my distance to your station (or to ...)?	Your distance to my station (or to ...) is ... (distance figures and units).
QGH	May I land using ... (procedure or facility)?	You may land using ... (procedure or facility).
QGK	What track should I make good? or What track are you making good?	Make good a track from ... (place) on ... degrees ... (true or magnetic). or I am making good a track from ... (place) on ... degrees ... (true or magnetic).
QGL	May I enter the ... (control area or zone) at ... (place)?	You may enter the ... (control area or zone) at ... (place).
QGM		Leave the ... (control area or zone).
QGN	May I be cleared to land [at ... (place)]?	You are cleared to land [at ... (place)].
QGO		Landing is prohibited at ... (place).
QGP	What is my number for landing?	You are number ... to land.
QGQ	May I hold at ... (place)?	Hold at ... (place) at flight level/altitude ... (datum) and await further clearance.
QGT		Fly for ... minutes on a heading what will enable you to maintain a track reciprocal to your present one.
QGU		Fly for ... minutes on a magnetic heading of ... degrees.
QGV	Do you see me? or Can you see the aerodrome? or Can you see ... (aircraft)?	I see you at ... (cardinal or quadrantal point of direction). or I can see the aerodrome. or I can see ... (aircraft).
QGW	Does my landing gear appear to be down and in place?	Your landing gear appears to be down and in place.
QGZ		Hold on ... direction of ... facility.
QHE	Will you inform me when you are on ... leg of approach?	I am on ... 1) cross-wind leg 2) down-wind leg 3) base leg 4) final leg ... of approach.
QHG	May I enter traffic circuit at flight level/altitude ...?	Cleared to enter traffic circuit at flight level/altitude ...
QHH	Are you making an emergency landing?	I am making an emergency landing. or Emergency landing being made at ... (place). All aircraft below flight level/altitude ... and within a distance of ... (figures and units) leave ... (place or headings).
QHI	Are you (or is ...) ... 1) waterborne? 2) on land?	I am (or ... is) ... 1) waterborne 2) on land at ... hours.
QHQ	May I make a ... approach [at ... (place)]? or Are you making a ... approach?	You may make a ... approach [at ... (place)]. or I am making a ... approach.
QHZ	Shall I circle the aerodrome (or go around)?	Circle the aerodrome (or go around).
QIC	May I establish communication with ... radio station on ... kHz (or ... MHz.) now (or at ... hours)?	Establish communication with ... radio station on ... kHz. (or MHz.) now (or at ...hours). or I will establish communication with ... radio station on ... kHz (or ... MHz) now (or at ... hours).
QIF	What frequency is ... using?	... is using ... kHz (or ... MHz.).
QJA	Is my ... 1) tape 2) mark and space reversed?	Your ... 1) tape 2) mark and space is reversed.
QJB	Will you use ... 1) radio? 2) cable? 3) telegraph? 4) teletypewriter? 5) telephone? 6) receiver? 7) transmitter? 8) reperforator?	I will use ... 1) radio. 2) cable. 3) telegraph. 4) teletypewriter. 5) telephone. 6) receiver. 7) transmitter. 8) reperforator.
QJC	Will you check your ... 1) transmitter distributor? 2) auto-head? 3) perforator? 4) reperforator? 5) printer? 6) printer motor? 7) keyboard? 8) antenna system?	I will check my ... 1) transmitter distributor. 2) auto-head. 3) perforator. 4) reperforator. 5) printer. 6) printer motor. 7) keyboard. 8) antenna system.
QJD	Am I transmitting ... 1) in letters? 2) in figures?	You are transmitting ... 1) in letters 2) in figures.
QJE	Is my frequency shift ... 1) too wide? 2) too narrow? 3) correct?	Your frequency shift is ... 1) too wide. 2) too narrow (by ... cycles). 3) correct.
QJF		My signal as checked by monitor ... is satisfactory ... 1) locally. 2) as radiated.
QJG	Shall I revert to automatic relay?	Revert to automatic relay.
QJH	Shall I run ... 1) my test tape? 2) a test sentence?	Run ... 1) your test tape. 2) a test sentence.
QJI	Will you transmit a continuous ... 1) mark? 2) space?	I am transmitting a continuous... 1) mark. 2) space.
QJK	Are you receiving ... 1) a continuous mark? 2) a continuous space? 3) a mark bias? 4) a space bias?	I am receiving ... 1) a continuous mark. 2) a continuous space. 3) a mark bias. 4) a space bias.
QKC		The sea conditions (at ... position) ... 1) permit alighting but not take-off. 2) render alighting extremely hazardous.
QKF	May I be relieved (at ... hours)?	You may expect to be relieved at ... hours [by ... 1) aircraft ... (identification) (type ...) 2) vessel whose call sign is ... (call sign) {and/or whose name is ... (name)}].
QKG	Will relief take place when ... (identification) establishes ... 1) visual, 2) communications, contact with survivors?	Relief will take place when ... (identification) establishes ... 1) visual, 2) communications, contact with survivors.
QKH	Report details of the parallel sweep (track) search being (or to be) conducted? or In the parallel sweep (track) search being (or to be) conducted, what is (are) ... 1) the direction of sweeps, 2) the separation between sweeps, 3) the flight level/altitude ... employed in the search pattern?	The parallel sweep (track) search is being (or to be) conducted ... 1) with direction of sweeps ... degrees ... (true or magnetic). 2) with ... (distance figures and units) separation between sweeps. 3) at flight level/altitude ...
QKN		Aircraft plotted (believed to be you) in position ... on track ... degrees at ... hours.
QKO	What other units are (or will be) taking part in the operation [... (identification of operation)]?	In the operation [... (identification)], the following units are (or will be) taking part ... (name of units). or ... (name) unit is taking part in operation [... (identification] (with effect from ... hours).
QKP	Which pattern of search is being followed?	The search pattern is ... 1) parallel sweep. 2) square search. 3) creeping line ahead. 4) track crawl. 5) contour search. 6) combined search by aircraft and ship. 7) ... (specify).
QLB	Will you monitor ... station and report regarding range, quality, etc.?	I have monitored ... station and report (briefly) as follows ...
QLH	Will you use simultaneous keying on ... frequency and ... frequency?	I will now key simultaneously on ... frequency and ... frequency.
QLV	Is the ... radio facility still required?	The ... radio facility is still required.
QMH		Shift to transmit and receive on ... kHz (or ... MHz.); if communication is not established within 5 minutes, revert to present frequency.
QMI	Report the vertical distribution of cloud [at ... (position or zone)] as observed from your aircraft.	The vertical distribution of cloud as observed from my aircraft at ... hours at ... (position or zone) is : lowest layer observed* ... eights (... type) with base of ... (figures and units) and tops of ... (figures and units) [*and similarly in sequence for each of the layers observed.] height above ... (datum).
QMU	What is the surface temperature at ... (place) and what is the dew point temperature at that place?	The surface temperature at ... (place) at ... hours is ... degrees and the dew point temperature at that time and place is ... degrees.
QMW	At ... (position or zone) what is (are) the flight level(s)/altitude(s) ... of the zero Celsius isotherm(s)?	At ... (position or zone) the zero Celsius isotherm(s) is (are) at flight level(s)/altitude(s) ...
QMX	What is the air temperature [at ... (position or zone)] (at ... hours) at flight level/altitude ...?	At ... (position or zone) at ... hours the air temperature is ... (degrees and units) at flight level/altitude ... Note.- Aircraft reporting QMX information will transmit the temperature figures as corrected for airspeed.
QMZ	Have you any amendments to the flight forecast in respect of section of route yet to be traversed?	The following amendment(s) should be made to the flight forecast ... [If no amendments, signal QMZ NIL]
QNE	What indication will my altimeter give on landing at ... (place) at ... hours, my sub-scale being set to 1013.2 millibars (29.92 inches)?	On landing at ... (place) at ... hours, with your sub-scale being set to 1013.2 millibars (29.92 inches), your altimeter will indicate ... (figures and units).
QNH	What should I set on the subscale of my altimeter so that the instrument would indicate its elevation if my aircraft were on the ground at your station?	If you set the subscale of your altimeter to read ... millibars, the instrument would indicate its elevation if your aircraft were on the ground at my station at ... hours. Note.- When the setting is given in hundredths of inch the abbreviation INS is used to identify the units.
QNI	Between what heights above ... (datum) has turbulence been observed at ... (position or zone)?	Turblence has been observed at ... (position or zone) with an intensity of ... between ... (figures and units) and ... (figures and units) heights above ... (datum).
QNO		I am not equipped to give the information (or provide the facility) requested.
QNR		I am approaching my point of no return.
QNT	What is the maximum speed of the surface wind at ... (place)?	The maximum speed of the surface wind at ... (place) at ... hours is ... (speed figures and units).
QNY	What is the present weather and the intensity thereof at ... (place, position or zone)?	The present weather and intensity thereof at ... (place, position or zone) at ... hours is ... Notes: a) When present weather information is transmitted by a ground station, the abbreviations shall be selected from those specified in Annex 3, paragraph 4.8.2. b) When present weather information is transmitted by an aircraft, the information shall be selected from items 10 to 12 of the AIREP form.

Maritime Mobile Service (QOA–QQZ)

Main article Maritime Mobile Service Q Codes

This assignment is specified in RECOMMENDATION ITU-R M.1172.

Q signals are not substantially used in the maritime service. Morse code is now very rarely used for maritime communications, but in isolated maritime regions like Antarctica and the South Pacific the use of Q Codes continues. Q Codes still work when HF voice circuits are not possible due to atmospherics and the nearest vessel is one ionospheric hop away.

	Question ?	Answer or Advice
QOA	Can you communicate by radiotelegraphy (500 kHz)?	I can communicate by radiotelegraphy (500 kHz).
QOB	Can you communicate by radiotelephony (2182 kHz)?	I can communicate by radiotelephony (2182 kHz).
QOC	Can you communicate by radiotelephony (channel 16 - frequency 156.80 MHz)?	I can communicate by radiotelephony (channel 16 - frequency 156.80 MHz).
QOD	Can you communicate with me in ... 0. Dutch 5. Italian 1. English 6. Japanese 2. French 7. Norwegian 3. German 8. Russian 4. Greek 9. Spanish?	I can communicate with you in ... 0. Dutch 5. Italian 1. English 6. Japanese 2. French 7. Norwegian 3. German 8. Russian 4. Greek 9. Spanish.
QOE	Have you received the safety signal sent by ... (name and/or call sign)?	I have received the safety signal sent by ... (name and/or call sign).
QOF	What is the commercial quality of my signals?	The quality of your signals is ... 1. not commercial 2. marginally commercial 3. commercial.
QOG	How many tapes have you to send?	I have ... tapes to send.
QOH	Shall I send a phasing signal for ... seconds?	Send a phasing signal for ... seconds.
QOI	Shall I send my tape?	Send your tape.
QOJ	Will you listen on ... kHz (or MHz) for signals of emergency position-indicating radiobeacons?	I am listening on ... kHz (or MHz) for signals of emergency position-indicating radiobeacons.
QOK	Have you received the signals of an emergency position-indicating radiobeacon on ... kHz (or MHz)?	I have received the signals of an emergency position-indicating radiobeacon on ... kHz (or MHz).
QOL	Is your vessel fitted for reception of selective calls? If so, what is your selective call number or signal?	My vessel is fitted for the reception of selective calls. My selective call number or signal is ...
QOM	On what frequencies can your vessel be reached by a selective call?	My vessel can be reached by a selective call on the following frequency/ies ... (periods of time to be added if necessary).
QOO	Can you send on any working frequency?	I can send on any working frequency.
QOT	Do you hear my call; what is the approximate delay in minutes before we may exchange traffic?	I hear your call; the approximate delay is ... minutes.

All Services (QRA–QUZ)

First defined by the Washington 1927 ITU Radio Regulations. Later defined by ITU-R in Appendix 9 to the Radio Regulations Annex to the International Telecommunications Convention (Atlantic City) 1947. The current callsign table is found in ITU-R Appendix 42. Current interpretation of the Q-code can be found in ITU-R Appendices 14 and 15.

ITU Radio Regulations 1990, Appendix 13: Miscellaneous Abbreviations and Signals to Be Used in Radiotelegraphy Communications Except in the Maritime Mobile Service

	Question ?	Answer or Advice
QRA	What is the name of your vessel (or station)?	The name of my vessel (or station) is ...
QRB	How far approximately are you from my station?	The approximate distance between our stations is ... nautical miles (or km).
QRC	By what private enterprise (or state administration) are the accounts for charges for your station settled?	The accounts for charges of my station are settled by the private enterprise ... (or state administration).
QRD	Where are you bound for and where are you from?	I am bound for ... from ...
QRE	What is your estimated time of arrival at ... (or over ...) (place)?	My estimated time of arrival at ... (or over ...) (place) is ... hours.
QRF	Are you returning to ... (place)?	I am returning to ... (place). or Return to ... (place).
QRG	Will you tell me my exact frequency (or that of ...)?	Your exact frequency (or that of ...) is ... kHz (or MHz).
QRH	Does my frequency vary?	Your frequency varies.
QRI	How is the tone of my transmission?	The tone of your transmission is ... 1. good 2. variable 3. bad.
QRJ	How many radiotelephone calls have you to book?	I have ... radiotelephone calls to book.
QRK	What is the intelligibility of my signals (or those of ...)?	The intelligibility of your signals (or those of ...) is ... 1. bad 2. poor 3. fair 4. good 5. excellent.
QRL	Are you busy?	I am busy (or I am busy with ...). Please do not interfere.
QRM	Are you being interfered with? [AP13] or Is my transmission being interfered with? [AP14]	I am being interfered with [AP13] or Your transmission is being interfered with ... [AP14] (1. nil 2. slightly 3. moderately 4. severely 5. extremely).
QRN	Are you troubled by static?	I am troubled by static (1. nil 2. slightly 3. moderately 4. severely 5. extremely).
QRO	Shall I increase transmitter power?	Increase transmitter power.
QRP	Shall I decrease transmitter power?	Decrease transmitter power.
QRQ	Shall I send faster?	Send faster (... words per minute).
QRR	Are you ready for automatic operation?	I am ready for automatic operation. Send at ... words per minute.
QRS	Shall I send more slowly?	Send more slowly (... words per minute).
QRT	Shall I stop sending?	Stop sending.
QRU	Have you anything for me?	I have nothing for you.
QRV	Are you ready?	I am ready.
QRW	Shall I inform ... that you are calling him on ... kHz (or MHz)?	Please inform ... that I am calling him on ... kHz (or MHz).
QRX	When will you call me again?	I will call you again at ... hours (on ... kHz (or MHz)).
QRY	What is my turn? (Relates to communication).	Your turn is Number ... (or according to any other indication). (Relates to communication).
QRZ	Who is calling me?	You are being called by ... (on ... kHz (or MHz)).
QSA	What is the strength of my signals (or those of ...)?	The strength of your signals (or those of ...) is 1. scarcely perceptible 2. weak 3. fairly good 4. good 5. very good.
QSB	Are my signals fading?	Your signals are fading.
QSC	Are you a cargo vessel? [AP13] or Are you a low traffic ship? [AP14]	I am a cargo vessel. [AP13] or I am a low traffic ship. [AP14]
QSD	Is my keying defective? [AP13] or Are my signals mutilated? [AP14]	Your keying is defective. [AP13] or Your signals are mutilated. [AP14]
QSE*	What is the estimated drift of the survival craft?	The estimated drift of the survival craft is ... (figures and units).
QSF*	Have you effected rescue?	I have effected rescue and am proceeding to ... base (with ... persons injured requiring ambulance).
QSG	Shall I send ... telegrams at a time?	Send ... telegrams at a time.
QSH	Are you able to home on your direction-finding equipment?	I am able to home on my D/F equipment (on station ...).
QSI		I have been unable to break in on your transmission. or Will you inform ... (call sign) that I have been unable to break in on his transmission (on ... kHz (or MHz)).
QSJ	What is the charge to be collected to ... including your internal charge?	The charge to be collected to ... including my internal charge is ... francs.
QSK	Can you hear me between your signals and if so can I break in on your transmission?	I can hear you between my signals; break in on my transmission.
QSL	Can you acknowledge receipt?	I am acknowledging receipt.
QSM	Shall I repeat the last telegram which I sent you (or some previous telegram)?	Repeat the last telegram which you sent me (or telegram(s) number(s) ...).
QSN	Did you hear me (or ... (call sign)) on ... kHz (or MHz)?	I did hear you (or ... (call sign)) on ... kHz (or MHz).
QSO	Can you communicate with ... direct (or by relay)?	I can communicate with ... direct (or by relay through ...).
QSP	Will you relay to ... free of charge?	I will relay to ... free of charge.
QSQ	Have you a doctor on board (or is ... (name of person) on board)?	I have a doctor on board (or ... (name of person) is on board).
QSR	Shall I repeat the call on the calling frequency?	Repeat your call on the calling frequency; did not hear you (or have interference).
QSS	What working frequency will you use?	I will use the working frequency ... kHz (or MHz) (in the HF bands normally only the last three figures of the frequency need be given).
QSU	Shall I send or reply on this frequency (or on ... kHz (or MHz)) (with emissions of class ...)?	Send or reply on this frequency (or on ... kHz (or MHz)) (with emissions of class ...).
QSV	Shall I send a series of Vs on this frequency (or on ... kHz (or MHz))?	Send a series of Vs on this frequency (or on ... kHz (or MHz)).
QSW	Will you send on this frequency (or on ... kHz (or MHz)) (with emissions of class ...)?	I am going to send on this frequency (or on ... kHz (or MHz)) (with emissions of class ...).
QSX	Will you listen to ... (call sign(s)) on ... kHz (or MHz)? [AP13] or Will you listen to ... (call sign(s)) on ... kHz (or MHz), or in the bands ... / channels ... ? [AP14]	I am listening to ... (call sign(s)) on ... kHz (or MHz). [AP13] or I am listening to ... (call sign(s)) on ... kHz (or MHz), or in the bands ... / channels ... [AP14]
QSY	Shall I change to transmission on another frequency?	Change to transmission on another frequency (or on ... kHz (or MHz)).
QSZ	Shall I send each word or group more than once?	Send each word or group twice (or ... times).
QTA	Shall I cancel telegram (or message) number ... ?	Cancel telegram (or message) number ...
QTB	Do you agree with my counting of words?	I do not agree with your counting of words; I will repeat the first letter or digit of each word or group.
QTC	How many telegrams have you to send?	I have ... telegrams for you (or for ...).
QTD*	What has the rescue vessel or rescue aircraft recovered?	... (identification) has recovered ... 1. ... (number) survivors 2. wreckage 3. ... (number) bodies.
QTE	What is my TRUE bearing from you? or What is my TRUE bearing from ... (call sign)? or What is the TRUE bearing of ... (call sign) from ... (call sign)?	Your TRUE bearing from me is ... degrees at ... hours. or Your TRUE bearing from ... (call sign) was ... degrees at ... hours. or The TRUE bearing of ... (call sign) from ... (call sign) was ... degrees at ... hours.
QTF	Will you give me the position of my station according to the bearings taken by the direction-finding stations which you control?	The position of your station according to the bearings taken by the D/F stations which I control was ... latitude, ... longitude (or other indication of position), class ... at ... hours.
QTG	Will you send two dashes of ten seconds each followed by your call sign (repeated ... times) (on ... kHz (or MHz))? or Will you request ... to send two dashes of ten seconds followed by his call sign (repeated ... times) on ... kHz (or MHz)?	I am going to send two dashes of ten seconds each followed by my call sign (repeated ... times) (on ... kHz (or MHz)). or I have requested ... to send two dashes of ten seconds followed by his call sign (repeated ... times) on ... kHz (or MHz).
QTH	What is your position in latitude and longitude (or according to any other indication)?	My position is ... latitude, ... longitude (or according to any other indication).
QTI	What is your TRUE track? [AP13]	My TRUE track is ... degrees. [AP13]
QTI*	What is your TRUE course? [AP14]	My TRUE course is ... degrees. [AP14]
QTJ*	What is your speed? (Requests the speed of a ship or aircraft through the water or air respectively).	My speed is ... knots (or ... kilometres per hour or ... statute miles per hour). (Indicates the speed of a ship or aircraft through the water or air respectively).
QTK*	What is the speed of your aircraft in relation to the surface of the Earth?	The speed of my aircraft in relation to the surface of the Earth is ... knots (or ... kilometres per hour or ... statute miles per hour).
QTL*	What is your TRUE heading?	My TRUE heading is ... degrees.
QTM*	What is your MAGNETIC heading?	My MAGNETIC heading is ... degrees.
QTN	At what time did you depart from ... (place)?	I departed from ... (place) at ... hours.
QTO	Have you left dock (or port)? or Are you airborne?	I have left dock (or port). or I am airborne.
QTP	Are you going to enter dock (or port)? or Are you going to alight (or land)?	I am going to enter dock (or port). or I am going to alight (or land).
QTQ	Can you communicate with my station by means of the International Code of Signals (INTERCO)?	I am going to communicate with your station by means of the International Code of Signals (INTERCO).
QTR	What is the correct time?	The correct time is ... hours.
QTS	Will you send your call sign for tuning purposes or so that your frequency can be measured now (or at ... hours) on ... kHz (or MHz)? [AP13] or Will you send your call sign (and/or name) for ... seconds? [AP14]	I will send my call sign for tuning purposes or so that my frequency may be measured now (or at ... hours) on ... kHz (or MHz). [AP13] or I will send my call sign (and/or name) for ... seconds. [AP14]
QTT		The identification signal which follows is superimposed on another transmission.
QTU	What are the hours during which your station is open?	My station is open from ... to ... hours.
QTV	Shall I stand guard for you on the frequency of ... kHz (or MHz) (from ... to ... hours)?	Stand guard for me on the frequency of ... kHz (or MHz) (from ... to ... hours).
QTW*	What is the condition of survivors?	Survivors are in ... condition and urgently need ...
QTX	Will you keep your station open for further communication with me until further notice (or until ... hours)?	I will keep my station open for further communication with you until further notice (or until ... hours).
QTY*	Are you proceeding to the position of incident and if so when do you expect to arrive?	I am proceeding to the position of incident and expect to arrive at ... hours (on ... (date)).
QTZ*	Are you continuing the search?	I am continuing the search for ... (aircraft, ship, survival craft, survivors or wreckage).
QUA	Have you news of ... (call sign)?	Here is news of ... (call sign).
QUB*	Can you give me in the following order information concerning: the direction in degrees TRUE and speed of the surface wind; visibility; present weather; and amount, type and height of base of cloud above surface elevation at ... (place of observation)?	Here is the information requested: ... (The units used for speed and distances should be indicated.)
QUC	What is the number (or other indication) of the last message you received from me (or from ... (call sign))?	The number (or other indication) of the last message I received from you (or from ... (call sign)) is ...
QUD	Have you received the urgency signal sent by ... (call sign of mobile station)?	I have received the urgency signal sent by ... (call sign of mobile station) at ... hours.
QUE	Can you use telephony in ... (language), with interpreter if necessary; if so, on what frequencies? [AP13] or Can you speak in ... (language), - with interpreter if necessary; if so, on what frequencies? [AP14]	I can use telephony in ... (language) on ... kHz (or MHz). [AP13] or I can speak in ... (language) on ... kHz (or MHz). [AP14]
QUF	Have you received the distress signal sent by ... (call sign of mobile station)?	I have received the distress signal sent by ... (call sign of mobile station) at ... hours.
QUG	Will you be forced to alight (or land)? [AP13]	I am forced to alight (or land) immediately. or I shall be forced to alight (or land) at ... (position or place) at ... hours. [AP13]
QUH*	Will you give me the present barometric pressure at sea level?	The present barometric pressure at sea level is ... (units).
QUI	Are your navigation lights working? [AP13]	My navigation lights are working. [AP13]
QUJ	Will you indicate the TRUE track to reach you (or ...)? [AP13]	The TRUE track to reach me (or ...) is ... degrees at ... hours. [AP13]
QUK	Can you tell me the condition of the sea observed at ... (place or coordinates)? [AP13]	The sea at ... (place or coordinates) is ... [AP13]
QUL	Can you tell me the swell observed at ... (place or coordinates)? [AP13]	The swell at ... (place or coordinates) is ... [AP13]
QUM	May I resume normal working?	Normal working may be resumed.
QUN	1. When directed to all stations: [AP13,14] Will vessels in my immediate vicinity ... or (in the vicinity of ... latitude, ... longitude) or (in the vicinity of ...) please indicate their position, TRUE course and speed? or 2. When directed to a single station: [AP14] please indicate their position, TRUE course and speed?	My position, TRUE course and speed are ...
QUO*	Shall I search for ... 1. aircraft 2. ship 3. survival craft in the vicinity of ... latitude, ... longitude (or according to any other indication)?	Please search for ... 1. aircraft 2. ship 3. survival craft in the vicinity of ... latitude, ... longitude (or according to any other indication).
QUP	Will you indicate your position by 1. searchlight 2. black smoke trail 3. pyrotechnic lights?	My position is indicated by 1. searchlight 2. black smoke trail 3. pyrotechnic lights.
QUQ	Shall I train my searchlight nearly vertical on a cloud, occulting if possible and, if your aircraft is seen, deflect the beam up wind and on the water (or land) to facilitate your landing?	Please train your searchlight on a cloud, occulting if possible and, if my aircraft is seen or heard, deflect the beam up wind and on the water (or land) to facilitate my landing. [AP13]
QUR*	Have survivors ... 1. received survival equipment 2. been picked up by rescue vessel 3. been reached by ground rescue party?	Survivors ... 1. are in possession of survival equipment dropped by ... 2. have been picked up by rescue vessel 3. have been reached by ground rescue party.
QUS*	Have you sighted survivors or wreckage? If so, in what position?	Have sighted ... 1. survivors in water 2. survivors on rafts 3. wreckage in position ... latitude, ... longitude (or according to any other indication).
QUT*	Is position of incident marked?	Position of incident is marked by ... 1. flame or smoke float 2. sea marker 3. sea marker dye 4. ... (specify other marking).
QUU*	Shall I home ship or aircraft to my position?	Home ship or aircraft ... (call sign) ... 1. to your position by transmitting your call sign and long dashes on ... kHz (or MHz) 2. by transmitting on ... kHz (or MHz) TRUE track to reach you.
QUW*	Are you in the search area designated as ... (designator or latitude and longitude)?	I am in the ... (designation) search area.
QUX	Do you have any navigational warnings or gale warnings in force? [AP14]	I have the following navigational warning(s) or gale warning(s) in force: ... [AP14]
QUY*	Is position of survival craft marked?	Position of survival craft was marked at ... hours by ... 1. flame or smoke float 2. sea marker 3. sea marker dye 4. ... (specify other marking).
QUZ	May I resume restricted working? [AP14]	Distress phase still in force; restricted working may be resumed. [AP14]

Amateur radio

Amateur radio actually has adapted two different sets of Q codes for use in amateur communications. The first set come from the ITU civil series QRA through QUZ. Most of the meanings are identical to the ITU definitions, however, they must be looked at in the context of amateur communications. For example, QSJ? asks what the charges are for sending the telegraph. Since amateur communications are without charge, this Q code would not make sense.

The second set is the set of QN Signals, used only in ARRL NTS nets. These operating signals generally have no equivalent in the ACP 131 publication or ITU publications, and are specifically defined only for use in ARRL NTS nets. They are not used in casual amateur radio communications.

Selected Q codes were soon adopted by amateur radio operators. In December 1915, the American Radio Relay League began publication of a magazine titled QST, named after the Q code for "General call to all stations". In amateur radio, the Q codes were originally used in Morse code transmissions to shorten lengthy phrases and were followed by a Morse code question mark (··— —··) if the phrase was a question.

Q codes are commonly used in voice communications as shorthand nouns, verbs, and adjectives making up phrases. For example, an amateur radio operator will complain about QRM (man-made interference), or tell another operator that there is "QSB on the signal" (fading); "to QSY" is to change your operating frequency, or to break in on a conversation QSK is often used even on VHF and UHF frequencies. (See also Informal usage, below.)

Q codes as adapted for use in amateur radio

Code	Question	Answer or Statement
QLE	What is your expected signal?	The expected signal is low...
QNI	May I join the net?	You may check in...
QRA	What is the name (or call sign) of your station?	The name (or call sign) of my station is ...
QRG	Will you tell me my exact frequency (or that of ...)?	Your exact frequency (or that of ... ) is ... kHz (or MHz).
QRH	Does my frequency vary?	Your frequency varies.
QRI	How is the tone of my transmission?	The tone of your transmission is (1. Good; 2. Variable; 3. Bad)
QRJ	How many voice contacts do you want to make?	I want to make ... voice contacts.
QRK	What is the readability of my signals (or those of ...)?	The readability of your signals (or those of ...) is ... (1 to 5).
QRL	Are you busy?	I am busy. (or I am busy with ... ) Please do not interfere.
QRM	Do you have interference? [from other stations]	I have interference.
QRN	Are you troubled by static?	I am troubled by static.
QRO	Shall I increase power?	Increase power.
QRP	Shall I decrease power?	Decrease power.
QRQ	Shall I send faster?	Send faster (... wpm)
QRS	Shall I send more slowly?	Send more slowly (... wpm)
QRT	Shall I cease or suspend operation?/ shutoff the radio	I am suspending operation. /shutting off the radio
QRU	Have you anything for me?	I have nothing for you.
QRV	Are you ready?	I am ready.
QRW	Shall I inform ... that you are calling him on ... kHz (or MHz)?	Please inform ... that I am calling him on ... kHz (or MHz).
QRX	Shall I standby / When will you call me again?	Please standby / I will call you again at ... (hours) on ... kHz (or MHz)
QRZ	Who is calling me?	You are being called by ... on ... kHz (or MHz)
QSA	What is the strength of my signals (or those of ... )?	The strength of your signals (or those of ...) is ... (1 to 5).
QSB	Are my signals fading?	Your signals are fading.
QSD	Is my keying defective?	Your keying is defective.
QSG	Shall I send ... telegrams (messages) at a time?	Send ... telegrams (messages) at a time.
QSK	Can you hear me between your signals?	I can hear you between my signals.
QSL	Can you acknowledge receipt?	I am acknowledging receipt.
QSM	Shall I repeat the last telegram (message) which I sent you, or some previous telegram (message)?	Repeat the last telegram (message) which you sent me (or telegram(s) (message(s)) numbers(s) ...).
QSN	Did you hear me (or ... (call sign)) on .. kHz (or MHz)?	I did hear you (or ... (call sign)) on ... kHz (or MHz).
QSO	Can you communicate with ... direct or by relay?	I can communicate with ... direct (or by relay through ...).
QSP	Will you relay a message to ...?	I will relay a message to ... .
QSR	Do you want me to repeat my call?	Please repeat your call; I did not hear you.
QSS	What working frequency will you use?	I will use the working frequency ... kHz (or MHz).
QST	–	Here is a broadcast message to all amateurs.
QSU	Shall I send or reply on this frequency (or on ... kHz (or MHz))?	Send or reply on this frequency (or on ... kHz (or MHz)).
QSW	Will you send on this frequency (or on ... kHz (or MHz))?	I am going to send on this frequency (or on ... kHz (or MHz)).
QSX	Will you listen to ... (call sign(s) on ... kHz (or MHz))?	I am listening to ... (call sign(s) on ... kHz (or MHz))
QSY	Shall I change to transmission on another frequency?	Change to transmission on another frequency (or on ... kHz (or MHz)).
QSZ	Shall I send each word or group more than once?	Send each word or group twice (or ... times).
QTA	Shall I cancel telegram (message) No. ... as if it had not been sent?	Cancel telegram (message) No. ... as if it had not been sent.
QTC	How many telegrams (messages) have you to send?	I have ... telegrams (messages) for you (or for ...).
QTH	What is your position in latitude and longitude (or according to any other indication)?	My position is ... latitude...longitude
QTR	What is the correct time?	The correct time is ... hours
QTU	At what times are you operating?	I am operating from ... to ... hours.
QTX	Will you keep your station open for further communication with me until further notice (or until ... hours)?	I will keep my station open for further communication with you until further notice (or until ... hours).
QUA	Have you news of ... (call sign)?	Here is news of ... (call sign).
QUC	What is the number (or other indication) of the last message you received from me (or from ... (call sign))?	The number (or other indication) of the last message I received from you (or from ... (call sign)) is ...
QUD	Have you received the urgency signal sent by ... (call sign of mobile station)?	I have received the urgency signal sent by ... (call sign of mobile station) at ... hours.
QUE	Can you speak in ... (language), – with interpreter if necessary; if so, on what frequencies?	I can speak in ... (language) on ... kHz (or MHz).
QUF	Have you received the distress signal sent by ... (call sign of mobile station)?	I have received the distress signal sent by ... (call sign of mobile station) at ... hours.

Notes for response to radiotelegraph Q-codes: Responses to a radiotelegraph Q-code query or a Q-code assertion may vary depending upon the code. For Q-code assertions or queries which only need to be acknowledged as received, the usual practice is to respond with the letter "R" for "Roger" which means "Received correctly". Sending an "R" merely means the code has been correctly received and does not necessarily mean that the receiving operator has taken any other action. For Q-code queries that need to be answered in the affirmative, the usual practice is to respond with the letter "C" (Sounds like the Spanish word "Si"). For Q-code queries that need to be answered in the negative, the usual practice it to respond with the letter "N" for "no". For those Q-code assertions that merely need to be acknowledged as understood, the usual practice is to respond with the prosign <SN> or <VE> which means "understood". On telegraph cable networks "KK" was often used at the end of a reply to a Q Code to mean "OK" or "Acknowledged". This practice predates amateur radio as telegraph operators in the late 19th Century are known to have used it.

Informal usage

Chart of the Morse code letters and numerals.

QLF – "Are you sending with your left foot? Try sending with your left foot!" A humorously derogatory comment about the quality of a person's sending.

QSK – "I can hear you during my transmission" – refers to a particular mode of Morse code operating often called QSK operation (full break-in) in which the receiver is quickly enabled during the spaces between the dits and dahs, which allows another operator to interrupt transmissions. Many modern transceivers incorporate this function, sometimes referred to as full break-in as against semi-break-in in which there is a short delay before the transceiver goes to receive.

QSY – "Change to transmission on another frequency"; colloquially, "move [=change address]". E.g., "When did GKB QSY from Northolt to Portishead....?"

QTH – "My location is…"; colloquially in voice or writing, "location". E.g., "The OCF [antenna] is an interesting build but at my QTH a disappointing performer."

QTHR – "At the registered location…"; Chiefly British in voice or writing, "Historically - the location in the printed Callbook. Modernly - as given in online government records for my callsign". E.g., "You can contact me QTHR"

German use during World War II

During World War II, according to Bletchley Park’s General Report on Tunny, German radio teleprinter networks used Q-codes to establish and maintain circuit connections.

In particular: QKP was to indicate the Lorenz cipher machine setting for each message and, QZZ to indicate that the daily key change was about to take place at the sender's station.

See also

• ACP-131
• NOTAM Code
• Amateur radio
• Brevity code
• International Code of Signals
• International maritime signal flags
• Morse code
• Prosigns for Morse code
• QRA locator
• QSK operation (full break-in)
• Ten-code
• Z code

External links

• Easy to read Q Code graphic.
• Handbook for Wireless Telegraph Operators, October, 1909.
• Radio Laws and Regulations of the United States: Edition July 27, 1914. (Includes the 1912 London Radiotelegraphic Convention)
• List of Q codes
• A resource for Morse Code operation in the amateur radio hobby
• Amateur Radio Q Codes
• "Q-Signals"
• Radiotelegraph and Radiotelephone Codes, Prowords And Abbreviations
• Recommendation ITU-R M.1172