† When radio telephony is used, the abbreviations and terms are transmitted as spoken words.
‡ When radio telephony is used, the abbreviations and terms using the individual letters in non - phonetic form.
* Signal is also available for use in communicating with the maritime service.
# Signal for use in the teletypewriter service only.
† When radio telephony is used, the abbreviations and terms are transmitted as spoken words.
‡ When radio telephony is used, the abbreviations and terms are transmitted using the individual letters in non-phonetic form.
| A - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| ...L | Left (preceded by runway designation number to identify a parallel runway) |
| L - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| ...M | Metres (preceded by figures) |
| M - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| ...R | Right (preceded by runway designation number to identify a parallel runway) |
| R - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| ...T | True (preceded by bearing to indicate reference to True North) |
| T - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| ...V... | Variations from the mean wind direction (preceded and followed by figures in METAR / SPRECI, e.g. 350V070) |
| V - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| A | Amber |
| A/A | Air-to-air |
| A/G | Air-to-ground |
| AA/M | Aircraft autonomous integrity monitoring |
| AAA | (or AAB, AAC . . . etc., in sequence) Amended meteorological message (message type designator) |
| AAD | Assigned altitude deviation |
| AAL | Above aerodrome level |
| AAR | Air to air refuelling |
| ABI | Advance boundary information |
| ABM | Abeam |
| ABN | Aerodrome beacon |
| ABT | About |
| ABV | Above |
| AC | Altocumulus |
| ACARS | (to be pronounced "AY-CARS") Aircraft communication addressing and reporting system |
| ACAS | Airborne collision avoidance system |
| ACC ‡ | Area control centre or area control |
| ACCID | Notification of an aircraft accident |
| ACFT | Aircraft |
| ACK | Acknowledge |
| ACL | Altimeter check location |
| ACN | Aircraft classification number |
| ACP | Acceptance (message type designator) |
| ACPT | Accept or accepted |
| ACT | Active or activated or activity |
| AD | Aerodrome |
| ADA | Advisory area |
| ADC | Aerodrome chart |
| ADDN | Addition or additional |
| ADF ‡ | Automatic direction-finding equipment |
| ADIZ | (to be pronounced "AY-DIZ") Air defence identification zone |
| ADJ | Adjacent |
| ADO | Aerodrome office (specify service) |
| ADR | Advisory route |
| ADS* | The address (when this abbreviation is used to request a repetition, the question mark (IMI) precedes the abbreviation, e.g. IMI ADS) (to be used in AFS as a procedure signal) |
| ADS-B‡ | Automatic dependent surveillance - broadcast |
| ADS-C‡ | Automatic dependent surveillance - contract |
| ADSU | Automatic dependent surveillance unit |
| ADVS | Advisory service |
| ADZ | Advise |
| AES | Aircraft earth station |
| AFIL | Flight plan filed in the air |
| AFIS | Aerodrome flight information service |
| AFM | Yes or affirm or affirmative or that is correct |
| AFS | Aeronautical fixed service |
| AFT | After . . . (time or place) |
| AFTN ‡ | Aeronautical fixed telecommunication network |
| AGA | Aerodromes, air routes and ground aids |
| AGL | Above ground level |
| AGN | Again |
| AIC | Aeronautical information circular |
| AIDC | Air traffic services inter - facility data communication |
| AIM | Aeronautical information management |
| AIP | Aeronautical information publication |
| AIRAC | Aeronautical information regulation and control |
| AIREP | Air-report |
| AIRMET | Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations |
| AIS | Aeronautical information services |
| ALA | Alighting area |
| ALERFA ‡ | Alert phase |
| ALR | Alerting (message type designator) |
| ALRS | Alerting service |
| ALS | Approach lighting system |
| ALT | Altitude |
| ALTN | Alternate or alternating (light alternates in colour) |
| ALTN | Alternate (aerodrome) |
| AMA | Area minimum altitude |
| AMD | Amend or amended (used to indicate amended meteorological message; message type designator) |
| AMDT | Amendment (AIP Amendment) |
| AMS | Aeronautical mobile service |
| AMSL | Above mean sea level |
| AMSS | Aeronautical mobile satellite service |
| ANC | Aeronautical chart 1:500 000 (followed by name/title and scale) |
| ANCS | Aeronautical navigation chart - small scale (followed by name/title and scale) |
| ANS | Answer |
| AOC | Aerodrome obstacle chart |
| AP | Airport |
| APAPI | (to be pronounced "AY PAPI") Abbreviated precision approach path indicator |
| APCH | Approach |
| APDC | Aircraft parking / docking chart (followed by name/title) |
| APN | Apron |
| APP | Approach control office or approach control or approach control service |
| APR | April |
| APRX | Approximate or approximately |
| APSG | After passing |
| APU | Auxiliary power unit |
| APV | Approve or approved or approval |
| ARC | Area chart |
| ARNG | Arrange |
| ARO | Air traffic services reporting office |
| ARP | Aerodrome reference point |
| ARP | Air - report (message type designator) |
| ARQ | Automatic error correction |
| ARR | Arrive or arrival |
| ARR | Arrival (message type designator) |
| ARS | Special air - report (message type designator) |
| ARST | Arresting (specify (part of) aircraft arresting equipment) |
| AS | Altostratus |
| ASAP | As soon as possible |
| ASC | Ascend to or ascending to |
| ASDA | Accelerate - stop distance available |
| ASE | Altimetry system error |
| ASHTAM | Special series of NOTAM notifying, by means of a specific format, change in activity of volcano, a volcanic eruption and / or volcanic ash cloud that is of significance to aircraft operations |
| ASPH | Asphalt |
| AT - VASIS | (to be pronounced "AY - TEE - VASIS") |
| AT... | At (followed by time at which weather change is forecast to occur) |
| ATA‡ | Actual time of arrival |
| ATCSMAC... | Air traffic control surveillance minimum altitude chart (followed by name / title) |
| ATC‡ | Air traffic control (in general) |
| ATD‡ | Actual time of departure |
| ATFM | Air traffic flow management |
| ATIS | Automatic terminal information service |
| ATM | Air traffic management |
| ATN | Aeronautical telecommunication network |
| ATP... | At... (time or place) |
| ATS | Air traffic services |
| ATTN | Attention |
| ATZ | Aerodrome traffic zone |
| AUG | August |
| AUTH | Authorized or authorization |
| AUTO | Automatic |
| AUW | All up weight |
| AUX | Auxiliary |
| AVBL | Available or availability |
| AVG | Average |
| AVGAS | Aviation gasoline |
| AWOS | Automated weather observation system |
| AWTA | Advise at what table able |
| AWY | Airway |
| AZM | Azimuth |
| B - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| B | |
| B | Blue |
| BA | Braking action |
| BARO - VNAV | (to be pronounced "BAA - RO - VEE - NAV") Barometric vertical navigation |
| BASE | Cloud base |
| BCFG | Fog patches |
| BCN | Beacon (aeronautical ground light) |
| BCST | Broadcast |
| BDRY | Boundary |
| BECMG | Becoming |
| BFR | Before |
| BKN | Broken |
| BL... | Blowing (followed by DU = dust, SA = sand or SN = snow) |
| BLDG | Building |
| BLO | Below clouds |
| BLW | Below... |
| BOMB | Bombing |
| BR | Mist |
| BRF | Short (used to indicate the type of approach desired or required) |
| BRG | Bearing |
| BRKG | Braking |
| BS | Commercial broadcasting station |
| BTL | Between layers |
| BTN | Between |
| BUFR | Binary universal form for the representation of meteorological data |
| C - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| C | |
| C | Centre (preceded by runway designation number to identify a parallel runway) |
| C | Degrees Celsius (Centigrade) |
| CA | Course to an altitude |
| CAA | Civil Aviation Authority or Civil Aviation Administration |
| CAT | Category |
| CAT | Clear air turbulance |
| CAVOK | (to be pronounced "KA - OH - KAY") Visibility, cloud and present weather better than prescribed values or conditions |
| CB‡ | (to be pronounced "CEE BEE") Cumulonimbus |
| CC | Cirocumulus |
| CCA | (or CCB, CCC...etc., in sequence) Correct meteorological message (message type designator) |
| CCO | Continuous climb operations |
| CD | Candela |
| CDN | Coordination (message type designator) |
| CDO | Continuous descent operations |
| CDR | Conditional route |
| CF | Change frequency to... |
| CF | Course to a fix |
| CFM* | Confirm or I confirm (to be used in AFS as a procedure signal) |
| CGL | Circling guidance light(s) |
| CH | Channel |
| CH# | This is a channel - continuity - check of transmission to permit comparison of your record of channel - sequence numbers of messages received on the channel (to be used in AFS as a procedure signal) |
| CHEM | Chemical |
| CHG | Modification (message type designator) |
| CI | Cirrus |
| CIDIN | Common ICAO data interchange network |
| CIV | Civil |
| CK | Check |
| CL | Centre line |
| CLA | Clear type of ice formation |
| CLBR | Calibration |
| CLD | Cloud |
| CLG | Calling |
| CLIMB - OUT | Climb - out area |
| CLR | Clear(s) or cleared to ... or clearance |
| CLRD | Runway(s) cleared (used in METAR / SPECI) |
| CLSD | Close or closed or closing |
| CM | Centimetre |
| CMB | Climb to or climbing to |
| CMPL | Completion or completed or complete |
| CNL | Cancel or cancelled |
| CNL | Flight plan cancellation (message type designator) |
| CNS | Communications, navigation and surveillance |
| COM | Communications |
| CONC | Concrete |
| COND | Condition |
| CONS | Continuous |
| CONST | Construction or constructed |
| CONT | Continue(s) or continued |
| COOR | Coordinate or coordination |
| COORD | Coordinates |
| COP | Change - over - point |
| COR | Correct or correction or corrected (used to indicate corrected meteorological message: message type designator) |
| COT | At the coast |
| COV | Cover or covered or covering |
| CPDLC‡ | Controller - pilot data link communications |
| CPL | Current flight plan (message type designator) |
| CRC | Cyclic redundancy check |
| CRM | Collision risk model |
| CRZ | Cruise |
| CS | Call sign |
| CS | Cirrostatus |
| CTA | Control area |
| CTAM | Climb to and maintain |
| CTC | Contact |
| CTL | Control |
| CTN | Caution |
| CTR | Control zone |
| CU | Cumulus |
| CUF | Cumuliform |
| CUST | Customs |
| CVR | Cockpit voice recorder |
| CW | Continuous wave |
| CWY | Clearway |
| D - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| D | |
| D | Downward (tendency in RVR during previous 10 minutes) |
| D - VOLMET | Data link VOLMET |
| D -ATIS | (to be pronounced "DEE - ATIS") Data link automatic terminal information service |
| D... | Danger area (followed by identification) |
| DA | Decision altitude |
| DCD | Double channel duplex |
| DCKG | Docking |
| DCP | Datum crossing point |
| DCPC | Direct controller - pilot communications |
| DCS | Double channel simplex |
| DCT | Direct (in relation to flight plan clearances and type of approach) |
| DE* | From (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal) |
| DEC | December |
| DEG | Degrees |
| DEP | Depart or departure |
| DEP | Departure (message type designator) |
| DEPO | Deposition |
| DER | Departure end of the runway |
| DES | Descent to or descending to |
| DEST | Destination |
| DESTRESFA | Distress phase |
| DEV | Deviation or deviating |
| DF | Direction finding |
| DFDR | Digital flight data recorder |
| DFTI | Distance from touchdown indicator |
| DH | Decision height |
| DIF | Diffuse |
| DIST | Distance |
| DIV | Divert or diverting |
| DLA | Delay or delayed |
| DLA | Delay (message type designator) |
| DLIC | Data link initiation capability |
| DLY | Daily |
| DME‡ | Distance measuring equipment |
| DNG | Danger or dangerous |
| DOF | Date of flight |
| DOM | Domestic |
| DP | Dew point temperature |
| DPT | Depth |
| DR | Dead reckoning |
| DR... | Low drifting (followed by DU = dust, SA = sand or SN = snow) |
| DRG | During |
| DS | Dust storm |
| DSB | Double side-band |
| DTAM | Descend to and maintain |
| DTG | Date - time group |
| DTHR | Displaced runway threshold |
| DTRT | Deteriorate or deteriorating |
| DTW | Dual tandem wheels |
| DU | Dust |
| DUC | Dense upper cloud |
| DUPE# | This is a duplicate message (to be used in AFS as a procedure signal) |
| DUR | Duration |
| DVOR | Doppler VOR |
| DW | Dual wheels |
| DZ | Drizzle |
| E - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| E | |
| E | East or eastern longitude |
| EAT | Expected approach time |
| EB | Eastbound |
| EDA | Elevation differential area |
| EDTO | Extended diversion time operations |
| EEE# | Error (to be used in AFS as a procedure signal) |
| EET | Estimated elapsed time |
| EFC | Expect further clearance |
| EFIS | (to be pronounced "EE - FIS") Electronic flight instrument system |
| EGNOS | (to be pronounced "EGG - NOS") EUROPEAN geostationary navigation overlay service |
| EHF | Extremely high frequency (30 000 to 300 000 MHZ) |
| ELBA | Emergency location beacon - aircraft |
| ELEV | Elevation |
| ELR | Extra long range |
| ELT | Emergency locater transmitter |
| EM | Emission |
| EMBD | Embedded in a layer (to indicate cumulonimbus embedded in layers of other clouds) |
| EMERG | Emergency |
| END | Stop - end (related to RVR) |
| ENE | East north east |
| ENG | Engine |
| ENR | En route |
| ENRC... | Enroute chart (followed by name / title) |
| EOBT | Estimated off - block time |
| EQN | Equatorial latitudes northern hemisphere |
| EQPT | Equipment |
| EQS | Equatorial latitudes southern hemisphere |
| ESE | East - south- east |
| EST | Estimate or estimated or estimate (message type indicator) |
| ETA‡* | Estimated time of arrival or estimating arrival |
| ETD‡ | Estimated time of departure or estimating departure |
| ETO | Estimated time over significant point |
| EUR RODEX | European regional OPMET data exchange |
| EV | Every |
| EVS | Enhanced vision system |
| EXC | Except |
| EXER | Exercises or exercising or exercise |
| EXP | Expect or expected or expecting |
| EXTD | Extend or extending |
| F - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| F | |
| F | Fixed |
| FA | Course from a fix to an altitude |
| FAC | Facilities |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FAP | Final approach point |
| FAS | Final approach segment |
| FATO | Final approach and take / off area |
| FAX | Facsimile transmission |
| FBL | Light (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBL RA = light rain) |
| FC | Funnel cloud (tornado or water spout) |
| FCST | Forecast |
| FCT | Friction coefficient |
| FDPS | Flight data processing system |
| FEB | February |
| FEW | Few |
| FG | Fog |
| FIC | Flight information centre |
| FIR‡ | Flight information region |
| FIS | Flight information service |
| FISA | Automated flight information service |
| FL | Flight level |
| FLD | Field |
| FLG | Flashing |
| FLR | Flares |
| FLT | Flight |
| FLTCK | Flight check |
| FLUC | Fluctuating or fluctuation or fluctuated |
| FLW | Follow(s) or following |
| FLY | Fly or flying |
| FM | Course from a fix to manual termination (used in navigation database coding) |
| FM | From |
| FM... | From (followed by time at which weather change is forecast to begin) |
| FMC | Flight management computer |
| FMS‡ | Flight management system |
| FMU | Flow management unit |
| FNA | Final approach |
| FPAP | Flight path alignment point |
| FPL | Filed flight plan (message type designator) |
| FPM | Feet per minute |
| FPR | Flight plan route |
| FR | Fuel remaining |
| FREQ | Frequency |
| FRI | Friday |
| FRNG | Firing |
| FRONT | Front (relating to weather) |
| FROST | Frost (used in aerodrome warning) |
| FRQ | Frequent |
| FSL | Full stop landing |
| FSS | Flight service station |
| FST | First |
| FT | Feet (dimensional unit) |
| FTE | Flight technical error |
| FTP | Fictitious threshold point |
| FTT | Flight technical tolerance |
| FU | Smoke |
| FZ | Freezing |
| FZDZ | Freezing drizzle |
| FZFG | Freezing fog |
| FZRA | Freezing rain |
| G - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| G | |
| G | Green |
| G... | Variations from the mean wind speed (gusts) (followed by figures in METAR / SPECI and TAF) |
| G/A | Ground - to - air |
| G/A/G | Ground - to - air and air - to - ground |
| GA | Go ahead, resume sending (to be used in AFS as a procedure signal) |
| GA | General aviation |
| GAGAN | GPS and geostationary earth orbit augmented navigation |
| GAIN | Airspeed or headwind gain |
| GAMET | Area forecast for low - level flights |
| GARP | GBAS azimuth reference point |
| GBAS | (to be pronounced "GEE - BAS") Ground - based augmentation system |
| GCA‡ | Ground controlled approach system or ground controlled approach |
| GEN | General |
| GEO | Geographic or true |
| GES | Ground earth station |
| GLD | Glider |
| GLONASS‡ | (to pronounced "GLO - NAS") Global orbiting navigation satellite system |
| GLS‡ | GBAS landing system |
| GMC... | Ground movement chart (followed by name / title) |
| GND | Ground |
| GNDCK | Ground check |
| GNSS‡ | Global navigation satellite system |
| GOV | Government |
| GP | Glide path |
| GPA | Glide path angle |
| GPIP | Glide path intercept point |
| GPS‡ | Global positioning system |
| GPU | Global power unit |
| GPWS‡ | Ground proximity warning system |
| GR | Hail |
| GRAS | (to be pronounced "GRASS") Ground - based regional augmentation system |
| GRASS | Grass landing area |
| GRIB | Processed meteorological data in the form of grid point values expressed in binary form (meteorological code) |
| GS | Ground speed |
| GS | Small hail and / or snow pellets |
| GUND | Geoid undulation |
| H - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| H | |
| H | High pressure area or the centre of high pressure |
| H... | Significant wave heigh (followed by figures in METAR / SPECI) |
| H24 | Continuous day and night service |
| HA | Holding / racetrack to an altitude |
| HAPI | Helicopter approach path indicator |
| HBN | Hazard beacon |
| HCH | Helicopter crossing height |
| HDF | High frequency direction - finding station |
| HDG | Heading |
| HEL | Helicopter |
| HF | Holding / racetrack to a fix |
| HF‡ | High frequency (3 000 to 30 000 KHZ) |
| HGT | Height or height above |
| HJ | Sunrise to sunset |
| HLDG | Holding |
| HLP | Heliport |
| HLS | Helicopter landing site |
| HM | Holding / racetrack to a manual termination |
| HN | Sunset to sunrise |
| HO | Service available to meet operational requirements |
| HOL | Holiday |
| HOSP | Hospital aircraft |
| HPA | Hectopascal |
| HR | Hours |
| HRP | Heliport reference point |
| HS | Service available during hours of scheduled operations |
| HSH | High latitudes southern hemisphere |
| HUD | Head - up display |
| HUM | Humanitarian |
| HURCN | Hurricane |
| HVDF | High and very high frequency direction - finding stations (at the same location) |
| HVY | Heavy |
| HVY | Heavy (used to indicate the intensity of weather phenomena e.g. HVY RA = heavy rain) |
| HX | No specific working hours |
| HYR | Higher |
| HZ | Haze |
| HZ | Hertz (cycle per second) |
| I - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| I | |
| IAC... | Instrument approach chart (followed by name / title) |
| IAF | Initial approach fix |
| IAO | In and out of clouds |
| IAP | Instrument approach procedure |
| IAR | Intersection of air routes |
| IAS | Indicated airspeed |
| IBN | Identification beacon |
| ICAO | International Civil Aviation Organization |
| ICÉ | Icing |
| ID | Identifier or identity |
| IDENT | Identification |
| IF | Intermediate approach fix |
| IFF | Identification friend / foe |
| IFR‡ | Instrument flight rules |
| IGA | International general aviation |
| ILS‡ | Instrument landing system |
| IM | Inner marker |
| IMC‡ | Instrument meteorological conditions |
| IMG | Immigration |
| IMI* | Interrogation sign (question mark) (to be used in AFS as a procedure signal) |
| IMPR | Improve or improving |
| IMT | Immediate or immediately |
| INA | Initial approach |
| INBD | Inbound |
| INC | In cloud |
| INCERFA | Uncertainty phase |
| INCORP | Incorporated |
| INFO | Information |
| INOP | Inoperative |
| INP | If not possible |
| INPR | In progress |
| INS | Inertial navigation system |
| INSTL | Install or installed or installation |
| INSTR | Instrument |
| INT | Intersection |
| INTL | International |
| INTRG | Interrogator |
| INTRP | Interrupt or interruption or interrupted |
| INTSF | Intensify or intensifying |
| INTST | Intensity |
| IR | Ice on runway |
| IRS | Inertial reference system |
| ISA | International standard atmosphere |
| ISB | Independent sideband |
| ISOL | Isolated |
| J - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| J | |
| JAN | January |
| JTST | Jet stream |
| JUL | July |
| JUN | June |
| K - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| K | |
| KG | Kilograms |
| KHZ | Kilohertz |
| KIAS | Knots indicated airspeed |
| KM | Kilometres |
| KMH | Kilometres per hour |
| KPA | Kilopascal |
| KT | Knots |
| KW | Kilowatts |
| L - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| L | |
| . - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| L | Litre |
| L | Locator |
| L | Low pressure area or the centre of low pressure |
| LAM | Logical acknowledgement (message type indicator) |
| LAN | Inland |
| LAT | Latitude |
| LCA | Local or locally or location or located |
| LDA | Landing distance available |
| LDAH | Landing distance available, helicopter |
| LDG | Landing |
| LDI | Landing direction indicator |
| LEN | Length |
| LF | Low frequency (30 to 300 KHZ) |
| LGT | Light or lighting |
| LGTD | Lighted |
| LIH | Light intensity high |
| LIL | Light intensity low |
| LIM | Light intensity medium |
| Line | Line (used in SIGMET) |
| LM | Locator, middle |
| LMT | Local mean time |
| LNAV | (to be pronounced "EL - NAV") Lateral navigation |
| LNG | Long (used to indicate the type of approach desired or required) |
| LO | Locator, outer |
| LOC | Localizer |
| LONG | Longitude |
| LORAN | LORAN (long range air navigation system) |
| LOSS | Airspeed or headwind loss |
| LPV | Localizer performance with vertical guidance |
| LR | The last message received by me was... (to be used in AFS as a procedure signal) |
| LRG | Long range |
| LS | The last message sent by me was... (to be used in AFS as a procedure signal) |
| LTA | Lower control area |
| LTD | Limited |
| LTP | Landing threshold point |
| LV | Light and variable (relating to wind) |
| LVE | Leave or leaving |
| LVL | Level |
| LVP | Low visibility procedures |
| LYR | Layer or layered |
| M - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| M | |
| . - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| M... | Mach number (followed by figures) |
| M... | Minimum value of runway visual range (followed by figures in METAR / SPECI) |
| MAA | Maximum authorized altitude |
| MAG | Magnetic |
| MAHF | Missed approach holding fix |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | At sea |
| MAR | March |
| MATF | Missed approach turning fix |
| MAX | Maximum |
| MAY | May |
| MBST | Microburst |
| MCA | Minimum crossing altitude |
| MCW | Modulated continuous wave |
| MDA | Minimum descent altitude |
| MDF | Medium frequency direction - finding station |
| MDH | Minimum descent height |
| MEA | Minimum en - route altitude |
| MEDEVAC | Medical evacuation flight |
| MEHT | Minimum eye height over threshold (for visual approach slope indicator systems) |
| MET | Meteorological or meteorology |
| MET REPORT | Local routine meteorological report (in abbreviated plain language) |
| METAR | Aerodrome routine meteorological report (in meteorological code) |
| MF | Medium frequency (300 to 3 000 KHZ) |
| MHA | Minimum holding altitude |
| MHDF | Medium and high frequency direction - finding stations (at same location MHVDE Medium, high and very high frequency direction - finding stations |
| MHZ | Megahertz |
| MID | Mid - point (related to RVR) |
| MIFG | Shallow fog |
| MIL | Military |
| MIN* | Minutes |
| MIS | Missing... (transmission identification) (to be used in AFS as a procedure signal) |
| MKR | Marker radio beacon |
| MLS‡ | Microwave landing system |
| MM | Middle marker |
| MNH | Middle latitudes northern hemisphere |
| MNM | Minimum |
| MNPS | Minimum navigation performance specifications |
| MNT | Monitor or monitoring or monitored |
| MNTN | Maintain |
| MOA | Military operating area |
| MOC | Minimum obstacle clearance (required) |
| MOCA | Minimum obstacle clearance altitude |
| MOD | Moderate (used to indicate the intensity of weather phenomena, interference or static reports e.g. MODRA = moderate rain) |
| MON | Above mountains |
| MON | Monday |
| MOPS | Minimum operational performance standards |
| MOTNE | Meteorological Operational Telecommunications Network Europe |
| MOV | Move or moving or movement |
| MPS | Metres per second |
| MRA | Minimum reception altitude |
| MRG | Medium range |
| MRP | ATS / MET reporting point |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSAS | (to be pronounced "EM -SAS") Multifunctional transport satellite (MTSAT) satellite - based augmention system |
| MSAW | Minimum safe altitude warning |
| MSG | Message |
| MSH | Middle latitudes southern hemisphere |
| MSL | Mean sea level |
| MSR# | Message... (transmission identification) has been misrouted (to used in AFS as a procedure signal) |
| MSSR | Monopulse secondary surveillance radar |
| MT | Mountain |
| MTOM | Maximum take - off mass |
| MTU | Metric units |
| MTW | Mountain waves |
| MVDF | Medium and very high frequency direction - finding stations (at the same location) |
| MWO | Meteorological watch office |
| MX | Mixed type of ice formation (white and clear) |
| N - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| N | |
| N | No distinct tendency (in RVR during previous 10 minutes) |
| N | North or northern latitude |
| NADP | Noise abatement departure procedure |
| NASC | National AIS system centre |
| NAT | North Atlantic |
| NAV | Navigation |
| NAVAID | Navigation aid |
| NB | Northbound |
| NBD‡ | Non - directional radio beacon |
| NBFR | Not before |
| NC | No change |
| NCD | No cloud detected (used in automated METAR / SPECI) |
| NDV | No directional variations available (used in automated METAR / SPECI) |
| NE | North - east |
| NEB | North - eastbound |
| NEG | No or negative or permission not granted or that is not correct |
| NGT | Night |
| NIL* | None or I have nothing to send to you |
| NM | Nautical miles |
| NML | Normal |
| NN | No name, unnamed |
| NNE | North - north - east |
| NNW | North - north - west |
| NO | No (negative) (to used in AFS as a procedure signal) |
| NOF | International NOTAM office |
| NONSTD | Non - standard |
| NOSIG | No significant change (used in trend - type landing forecasts) |
| NOTAM | Notice distribution by means of telecommunication containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations |
| NOTAMC | Cancelling NOTAM |
| NOTAMN | New NOTAM |
| NOTAMR | Replacing NOTAM |
| NOV | November |
| NOZ‡ | Normal operating zone |
| NPA | Non precision approach |
| NR | Number |
| NRH | No reply heard |
| NS | Nimbostratus |
| NSC | Nil significant cloud |
| NSE | Navigation system error |
| NSW | Nil significant weather |
| NTL | National |
| NTZ‡ | No transgression zone |
| NW | North - west |
| NWB | North - westbound |
| NXT | Next |
| O - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| O | |
| O/R | On request |
| OAC | Oceanic area control centre |
| OAS | Obstacle assessment surface |
| OBS | Observe or observed or observation |
| OBSC | Obscure or obscured or obscuring |
| OBST | Obstacle |
| OCA | Oceanic clearance altitude |
| OCA | Obstacle control area |
| OCC | Occulting (light) |
| OCH | Obstacle clearance height |
| OCNL | Occasional or occasionally |
| OCS | Obstacle clearance surface |
| OCT | October |
| OFZ | Obstacle free zone |
| OGN | Originate (to be used in AFS as a procedure signal) |
| OHD | Overhead |
| OIS | Obstacle identification surface |
| OK | We agree or It is correct (to be used in AFS as a procedure signal) |
| OLD | On - line data interchange |
| OM | Outer marker |
| OPA | Opaque, white type of ice formation |
| OPC | The control indicated is operational control |
| OPMET | Operational meteorological (information) |
| OPN | Open or opening or opened |
| OPR | Operator or operate or operative or operating or operational |
| OPS | Operations |
| ORD | Order |
| OSV | Ocean station vessel |
| OTP | On top |
| OTS | Organized track system |
| OUBD | Outbound |
| OVC | Overcast |
| P - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| P | |
| P... | Maximum value of wind speed or runway visual range (followed by figures in METAR / SPECI and TAF) |
| P... | Prohibited area (followed by identification) |
| PA | Precision approach |
| PALS | Precision approach lighting system (specify category) |
| PANS | Procedures for air navigation services |
| PAPI | Precision approach path indicator |
| PARL | Parallel |
| PAR‡ | Precision approach radar |
| PATC... | Precision approach terrain chart (followed by name / title) |
| PAX | Passenger(s) |
| PBC | Performance - based communication |
| PBN | Performance - based navigation |
| PBS | Performance - based surveillance |
| PCD | Proceed or proceeding |
| PCD‡ | Pre - departure clearance |
| PCL | Pilot - controlled lighting |
| PCN | Pavement classification number |
| PCT | Per cent |
| PDG | Procedure design gradient |
| PER | Performance |
| PERM | Permanent |
| PIB | Pre - flight information bulletin |
| PJE | Parachute jumping exercise |
| PL | Ice pellets |
| PLA | Practice low approach |
| PLVL | Present level |
| PN | Prior notice required |
| PNR | Point of no return |
| PO | Dust / sand whirls (dust devils) |
| POB | Persons on board |
| POSS | Possible |
| PPI | Plan position indicator |
| PPR | Prior permission required |
| PPSN | Present position |
| PRFG | Aerodrome partially covered by fog |
| PRI | Primary |
| PRKG | Parking |
| PROB | Probability |
| PROC | Procedure |
| PROP | Propeller |
| PROV | Provisional |
| PRP | Point - in - space reference point |
| PS | Plus |
| PSG | Passing |
| PSN | Position |
| PSP | Pierced steel plank |
| PSR‡ | Primary surveillance radar |
| PSYS | Pressure systems |
| PTN | Procedure turn |
| PTS | Polar track structure |
| PWR | Power |
| Q - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| Q | |
| QDL | Do you intend to ask me for a series of bearings? Or I intend to ask you for a series of bearings (to be used in radio telegraphy as a Q code) |
| QDM‡ | Magnetic heading (zero wind) |
| QDR | Magnetic bearing |
| QFE‡ | Atmospheric pressure at aerodrome elevation (or at runway threshold) |
| QFU | Magnetic orientation on runway |
| QGE | What is my distance to your station? Or your distance to my station is (distance figures and units) (to be used in radio telegraphy as a Q code) |
| QJH | Shall I run my test tape / a test sentence? Or run your test tape / a test sentence (to be used in AFS as a Q code) |
| QNH‡ | Altimeter sub - scale setting to obtain elevation when on the ground |
| QSP | Will you relay to...free of charge? Or I will relay to... free of charge (to be used in AFS as a Q code) |
| QTA | Shall I cancel telegram number...? Or cancel telegram number...(to be used in AFS as a Q code) |
| QTE | True bearing |
| QTF | Will you give me the position of my station according to the bearings taken by the D / F stations which you control? or the position of your station the according to bearings taken by the D / F station I control was...latitude...logitude (or other indication of position), class...at...hours (to be used in radio telegraphy as a Q code) |
| QUAD | Quadrant |
| QUJ | Will you indicate the TRUE track to reach you? Or the TRUE track to reach me is...degrees at...hours (to be used in radio telegraphy as a Q code) |
| R - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| R | |
| . - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| R | Rate of turn |
| R | Red |
| R* | Received (acknowledgement of receipt) (to be used in AFS as a procedure signal) |
| R... | Radial from VOR (followed by figures) |
| R... | Restricted area (followed by identification) |
| R... | Runway (followed by figures in METAR / SPECI) |
| RA | Rain |
| RA | Resolution advisory |
| RAC | Rules of the air and air traffic services |
| RAG | Ragged |
| RAG | Runway arresting gear |
| RAI | Runway alignment indicator |
| RAIM | Receiver autonomous integrity monitoring |
| RASC | Regional AIS system centre |
| RASS | Remote altimeter setting source |
| RB | Rescue boat |
| RCA | Reach cruising altitude |
| RCC | Rescue coordination centre |
| RCF | Radio communication failure (message type designator) |
| RCH | Reach or reaching |
| RCL | Runway centre line |
| RCLL | Runway centre line light(s) |
| RCLR | Recleared |
| RCP‡ | Required communication performance |
| RDH | Reference datum height (for ILS) |
| RDL | Radial |
| RDO | Radio |
| RDOACT | Radioactive |
| RE | Recent (used to qualify weather phenomena, e.g. RERA = recent rain) |
| REC | Receive or receiver |
| REDL | Runway edge light(s) |
| REF | Reference to...or refer to... |
| REG | Registration |
| RENL | Runway end light(s) |
| REP | Report or reporting or reporting point |
| REQ | Request or requested |
| RERTE | Re - route |
| RESA | Runway end safety area |
| RF | Constant radius arc to a fix |
| RFFS | Rescue and fire fighting services |
| RG | Range (lights) |
| RHC | Right - hand circuit |
| RIF | Re-clearance in flight |
| RIME | Rime (used in aerodrome warnings) |
| RL | Report leaving |
| RLA | Relay to |
| RLCE | Request level change en - route |
| RLLS | Runway lead - in lighting system |
| RLNA | Request level not available |
| RMK | Remark |
| RNAV | (to be pronounced "AR - NAV") Area navigation |
| RNG | Radio range |
| RNP‡ | Required navigation performance |
| ROBEX | Regional OPMET bulletin exchange (scheme) |
| ROC | Rate of climb |
| ROD | Rate of descent |
| RON | Receiving only |
| RPDS | Reference path data selector |
| RPI‡ | Radar position indicator |
| RPL | Repetitive flight plan |
| RPLC | Replace or replaced |
| RPS | Radar position symbol |
| RPT* | Repeat or I repeat (to be used in AFS as a procedure signal) |
| RQ-* | Request (to be used in AFS as a procedure signal |
| RQMNT | Requirements |
| RQP | Requested flight plan (message type designator) |
| RQS | Request supplementary flight plan (message type designator) |
| RR | Report reaching |
| RRA | (or RRB,RRC,...etc., in sequence) Delayed meteorological message (message type designator) |
| RSC | Rescue sub - centre |
| RSCD | Runway surface condition |
| RSP | Responder beacon |
| RSP‡ | Required surveillance performance |
| RSR | En - route surveillance radar |
| RSS | Root sum square |
| RTD | Delayed (used to indicate delayed meteorological message; message type designator) |
| RTE | Route |
| RTF | Radio telephone |
| RTG | Radio telegraph |
| RTHL | Runway threshold light(s) |
| RTN | Return or returned or returning |
| RTODAH | Rejected take - off distance available, helicopter |
| RTS | Return to service |
| RTT | Radio teletype writer |
| RTZL | Runway touchdown zone light(s) |
| RUT | Standard regional route transmitting frequencies |
| RV | Rescue vessel |
| RVA | Radar vectoring area |
| RVR‡ | Runway visual range |
| RVSM‡ | Reduced vertical separation minimum (300 M (1000 FT) between FL 290 and FL 410) |
| RWY | Runway |
| S - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| S | |
| S | South or southern latitude |
| S... | State of the sea (followed by figures in METAR / SPECI) |
| SA | Sand |
| SALS | Simple approach lighting system |
| SAN | Sanitary |
| SAR | Search and rescue |
| SARPS | Standard and Recommended Practices (ICAO) |
| SAT | Saturday |
| SATCOM | Satellite communication |
| SATVOICE | Satellite voice communication |
| SB | Southbound |
| SBAS | (to be pronounced "ESS - BAS") Satellite - based augmentation system |
| SC | Stratocumulus |
| SCT | Scattered |
| SD | Standard deviation |
| SDBY | Standby |
| SDF | Step down fix |
| SE | South - east |
| SEA | Sea (used in connection with sea - surface temperature and state of the sea) |
| SEB | South - eastbound |
| SEC | Seconds |
| SECN | Section |
| SECT | Sector |
| SELCAL | Selective calling system |
| SEP | September |
| SER | Service or servicing or served |
| SEV | Severe (used e.g. to qualify icing and turbulence reports) |
| SFC | Surface |
| SG | Snow grains |
| SGL | Signal |
| SH... | Showers (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and / or snow pellets or combination of thereof e.g. SHRASN = Showers of rain and snow) |
| SHF | Super high frequency (3000 to 30000 MHZ) |
| SI | International system of units |
| SID | Standard instrument departure |
| SIF | Selective identification feature |
| SIG | Significant |
| SIGMET | Information concerning en - route weather and other phenomena in the atmosphere that may be affect the safety of aircraft operations |
| SIMUL | Simultaneous or simultaneously |
| SIWL | Single isolated wheel load |
| SKED | Schedule or scheduled |
| SLP | Speed limiting point |
| SLW | Slow |
| SMC | Surface movement control |
| SMR | Surface movement radar |
| SN | Snow |
| SNOCLO | Aerodrome closed due to snow (used in METAR / SPECI) |
| SNOWTAM | A special series of NOTAM given in a standard format providing a surface condition report notifying the presence or cessation of hazardous conditions due to snow, ice, slush, frost, standing water or water associated with snow, slush, ice or frost on the movement area |
| SOC | Start of climb |
| SPECI | Aerodrome special meteorological report (in meteorological code) |
| SPECIAL | Local special meteorological report ( in abbreviated plain language) |
| SPI | Special position indicator |
| SPL | Supplementary flight plan (message type designator) |
| SPOC | SAR point of contact |
| SPOT | Spot wind |
| SQ | Squall |
| SQL | Squall line |
| SR | Sunrise |
| SRA | Surveillance radar approach |
| SRE | Surveillance radar element of precision approach radar system |
| SRG | Short range |
| SRR | Search and rescue region |
| SRY | Secondary |
| SS | Sandstorm |
| SS | Sunset |
| SSB | Single sideband |
| SSE | South - south east |
| SSR‡ | Secondary surveillance radar |
| SST | Supersonic transport |
| SSW | South - south west |
| ST | Stratus |
| STA | Straight - in approach |
| STAR | Standard instrument arrival |
| STD | Standard |
| STF | Stratiform |
| STN | Station |
| STNR | Stationary |
| STOL | Short take - off and landing |
| STS | Status |
| STWL | Stopway light(s) |
| SUBJ | Subject to |
| SUN | Sunday |
| SUP | Supplement |
| SUPPS | Regional supplementary procedures |
| SVC | Service messages |
| SVCBL | Serviceable |
| SW | South - west |
| SWB | South - westbound |
| SWX | Space weather |
| SWXC | Space weather centre |
| SWY | Stopway |
| T - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| T | |
| T | Temperature |
| . - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| T-VASIS | (to be pronounced "TEE - VASIS") T visual approach slope indicator system |
| TA | Traffic advisory |
| TA | Transition altitude |
| TA/H | Turn at an altitude / height |
| TAA | Terminal arrival altitude |
| TACAN | UHF tactical air navigation aid |
| TADA | Take - off distance available |
| TAF | Aerodrome forecast (in meteorological code) |
| TAIL | Tail wind |
| TAR | Terminal area surveillance radar |
| TAS | True airspeed |
| TAX | Taxiing or taxi |
| TC | Tropical cyclone |
| TCAC | Tropical cyclone advisory centre |
| TCAS RA | (to be pronounced (" TEE -CAST - AR - AY ") Traffic alert and collision avoidance system resolution advisory |
| TCH | Threshold crossing height |
| TCU | Towering cumulus |
| TDO | Tornado |
| TDZ | Touchdown zone |
| TECR | Technical reason |
| TEL | Telephone |
| TEMPO | Temporary or temporarily |
| TF | Track to fix |
| TFC | Traffic |
| TGL | Touch - and - go landing |
| TGS | Taxiing guidance system |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIBA | Traffic information broadcast by aircraft |
| TIL | Until |
| TIP | Until past...(place) |
| TKOF | Take - off |
| TL... | Till (followed by which weather change is forcast to end) |
| TLOF | Touchdown and lift - off area |
| TMA‡ | Terminal control area |
| TN... | Minimum temperature (followed by figures in TAF) |
| TNA | Turn altitude |
| TNH | Turn height |
| TO... | To...(place) |
| TOC | Top of climb |
| TODAH | Take - off distance available, helicopter |
| TOP | Cloud top |
| TORA | Take - off run available |
| TOX | Toxic |
| TP | Turning point |
| TR | Track |
| TRA | Temporary reserved airspace |
| TRANS | Transmit or transmitter |
| TREND | Trend forecast |
| TRG | Training |
| TRL | Transition level |
| TROP | Tropopause |
| TS | Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome) |
| TS... | Thunderstorm (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and / or snow pellets or combination thereof e.g. TSRASN = thunderstorm with rain and snow) |
| TSUNAMI | Tsunami (used in aerodrome warnings) |
| TT | Teletype writer |
| TUE | Tuesday |
| TURB | Turbulence |
| TVOR | Terminal VOR |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TX... | Maximum temperature (followed by figures in TAF) |
| TXL | Taxilane |
| TXT* | Text (when the abbreviation is used to request a repetition, the question mark (IMI) precedes the abbreviation, e.g. IMI TXT) (to be used in AFS as a procedure signal) |
| TYP | Type of aircraft |
| TYPH | Typhoon |
| U - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| U | |
| U | Upward (tendency in RVR during previous 10 minutes) |
| U/S | Unserviceable |
| UA | Unmanned aircraft |
| UAB... | Until advised by... |
| UAC | Upper area control centre |
| UAR | Upper air route |
| UAS | Unmanned aircraft system |
| UDF | Ultra high frequency direction - finding station |
| UFN | Until further notice |
| UHDT | Unable higher due traffic |
| UHF‡ | Ultra high frequency (300 to 3000 MHZ) |
| UIC | Upper information centre |
| UIR‡ | Upper flight information region |
| ULM | Ultra light motorized aircraft |
| ULR | Ultra long range |
| UNA | Unable |
| UNAP | Unable to approve |
| UNL | Unlimited |
| UNREL | Unreliable |
| UP | Unidentified precipitation (used in automated METAR / SPECI) |
| UTA | Upper control area |
| UTC‡ | Coordinated Universal Time |
| V - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| V | |
| . - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| VA | Heading to an altitude |
| VA | Volcanic ash |
| VAAC | Volcanic ash advisory centre |
| VAC... | Visual approach chart (followed by name / title) |
| VAL | In valleys |
| VAN | Runway control van |
| VAR | Magnetic variation |
| VAR | Visual - aural radio range |
| VASIS | Visual approach slope indicator system |
| VC... | Vicinity of the aerodrome (followed by FG = fog, FC = funnel cloud, SH = shower, PO = dust / sand whirls, BLDU = blowing dust, BLSA = blowing sand or BLSN = blowing snow, DS = duststorm, SS = sandstorm, TS = thunderstorm or VA = volcanic ash, e.g.VCFG = vicinity fog) |
| VCY | Vicinity |
| VDF | Very high frequency direction - finding station |
| VER | Vertical |
| VFR‡ | Visual flight rules |
| VHF‡ | Very high frequency (30 to 300 MHZ) |
| VI | Heading to intercept |
| VIP‡ | Very important person |
| VIS | Visibility |
| VLF | Very low frequency (3 to 30 KHZ) |
| VLR | Very long range |
| VM | Heading to a manual termination |
| VMC | Visual meteorological conditions |
| VNAV | (to be pronounced "VEE - NAV") Vertical navigation |
| VOL... | Volume (followed by I, II...) |
| VOLMET | Meteorological information for aircraft in flight |
| VORTAC‡ | VOR and TACAN combination |
| VOR‡ | VHF omnidirectional radio range |
| VOT | VOR airborne equipment test facility |
| VPA | Vertical path angle |
| VPT | Visual manoeuvre with prescribed track |
| VRB | Variable |
| VSA | By visual reference to the ground |
| VSP | Vertical speed |
| VTF | Vector to final |
| VTOL | Vertical take - off and landing |
| VV... | Vertical visibility (followed by figures in METAR / SPECI and TAF) |
| W - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| W | |
| W | West or western longitude |
| W | White |
| W... | Sea - surface temperature (followed by figures in METAR / SPECI) |
| WAAS | Wide area augmentation system |
| WAC... | World Aeronautical Chart - ICAO 1:1000000 (followed by name / title |
| WAFC | World area forecast centre |
| WB | Westbound |
| WBAR | Wing bar lights |
| WDI | Wind direction indicator |
| WDSPR | Widespread |
| WED | Wednesday |
| WEF | With effect from or effective from |
| WGS - 84 | World Geodetic System - 1984 |
| WI | Within |
| WID | Width or wide |
| WIE | With immediate effect or effective immediately |
| WILCO | Will comply |
| WIND | Wind |
| WIP | Work in progress |
| WKN | Weaken or weakening |
| WNW | West - north - west |
| WO | Without |
| WPT | Way - point |
| WRNG | Warning |
| WS | Wind shear |
| WSPD | Wind speed |
| WSW | West - south - west |
| WT | Weight |
| WTSPT | Waterspout |
| WWW | Worldwide web |
| WX | Weather |
| WXR | Weather radar |
| X - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| X | |
| X | Cross |
| XBAR | Crossbar (of approach lighting system) |
| XNG | Crossing |
| XS | Atmospherics |
| Y - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| Y | |
| Y | Yellow |
| YCZ | Yellow caution zone (runway lighting) |
| YES* | Yes (affirmative) (to be used in AFS as a procedure signal) |
| YR | Your |
| Z - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
| Z | |
| Z | Coordinated Universal Time (in meteorological messages) |