List of acronyms: F

(Main list of acronyms)


 * f – (s) Femto
 * F – (s) Farad – Fluorine

FA

 * fa – (s) Persian language (ISO 639-1 code)
 * FA – Food Addicts in Recovery Anonymous
 * fA – (s) Femtoampere
 * FA
 * (i) Field Artillery
 * Financial aid
 * Football Association (England)
 * Football Australia (governing body for association football)
 * Forever Alone (Internet slang for “single”)
 * FAA
 * (i) U.S. Federal Aviation Administration
 * Financial Aid Administrator
 * Fleet Air Arm
 * Functional Area Analysis
 * FAAD – (a) Forward Area Air Defence
 * FAADEZ – (i) Forward Area Air Defence Engagement Zone
 * FAAN – (i) Fellow of the American Academy of Neurology
 * FAAFP – (i)Fellow of the American Academy of Family Physicians
 * FAAN – (i) Fellow of the American Academy of Nursing
 * FAANG – Facebook, Amazon, Apple, Netflix, Google (the leading stocks in the late-2010s US market rally) (c.f. FANG, which originally did not include Apple)
 * FAAQ – (a/i) Frequently Asked and Anticipated Questions (cf. FAQ)
 * FAASV – (i) Field Artillery Ammunition Supply Vehicle
 * FAB – (i) Feline Advisory Bureau (UK feline charity)
 * FACF - Fully Automatic Capsule Filler source
 * (i) Forward Air Controller
 * Front of Allies for Change
 * Frontal Affinity Chromatography
 * Full Aperture Calibrator
 * FACA – (a) (US) Federal Advisory Committee Act
 * FACH – (a) Fuerza Aérea de Chile
 * FACN – (i) Fellow of the American College of Nutrition
 * FACP – (i) Fellow of the American College of Physicians
 * FACS
 * (i) Fellow of the American College of Surgeons
 * (a) Formal Aspects of Computing Science
 * Fluorescent-activated cell sorting
 * FACTS – (a) Flexible Alternating Current Transmission System
 * FAD
 * (i) Flavin Adenine Dinucleotide
 * (a) Funding Authorization Document
 * M18 FADAC – (p) Field Artillery Data Computer
 * FADEC - (a) Full Authority Digital Engine (or Electronic) Control
 * FAFSA – (a) Free Application for Federal Student Aid (US)
 * FAH
 * (i) Federation of American Hospitals
 * Fine Arts and Humanities
 * Foreign Affairs Handbook
 * FAI
 * (i) Fédération Aéronautique Internationale (French, "International Aeronautics Federation")
 * Football Association of Ireland
 * FAL - (a) Fusil Automatique Léger (French, Light Automatic Rifle), Belgian battle rifle
 * FAM – (i) Foreign Affairs Manual
 * fao – (s) Faroese language (ISO 639-2 code)
 * FAO – (i) Food and Agriculture Organization
 * FAPA – Fellow of the American Psychological Association
 * FAPHA – Fellow of the American Public Health Association
 * FAQ – (a/i) Frequently Asked Questions (sometimes pronounced "fak")
 * FARC – (a) Fuerzas Armadas Revolucionarias de Colombia (Spanish, "Revolutionary Armed Forces of Colombia")
 * FARDC – (a) "Military of the Democratic Republic of the Congo
 * FARP – (a) Forward Arming and Refuelling Point / Forward Area Rearm/refuel Point
 * fas – (s) Persian language (ISO 639-2 code)
 * FAS
 * (i) Federation of American Scientists
 * Fetal Alcohol Syndrome
 * FASCAM – (p) Family of Scatterable Mines
 * FASD – (i) Fetal Alcohol Spectrum Disorder
 * FASEB – (a/i) Federation of American Societies for Experimental Biology
 * FAST
 * (a) Face, Arm, Speech, Time (stroke symptoms)
 * Five hundred meter Aperture Spherical Telescope (Chinese radio telescope)
 * Fixing America's Surface Transportation Act (U.S. legislation)
 * FAT – (a) Field Artillery Tractor – File Allocation Table
 * FAVS – (a) Future Armoured Vehicle System
 * FAW
 * (i) Football Association of Wales
 * First Automobile Works (Chinese automobile manufacturer)

FB

 * FB – Facebook, An on-line social network
 * FBCB2 or FBCB2 – (p) Force XXI Battle Command, Brigade-and-Below
 * FBCS – (i) Fellow of the British Computer Society
 * FBI – (i) Federal Bureau of Investigation
 * FBIS – (i) Foreign Broadcast Information Service
 * FBIDST – (i) Fellow of the British Institute of Dental and Surgical Technologists
 * FBM – (s) Board foot
 * FBR
 * (i) Fast Breeder Reactor
 * Foundation for Biomedical Research
 * Friedman, Billings, Ramsey (now known as Arlington Asset Investment)
 * FBS
 * Federal Bureau of Statistics (Pakistan)
 * Fetal bovine serum
 * Football Bowl Subdivision (U.S. college football)
 * Fukuoka Broadcasting Corporation

FC

 * fC – (s) Femtocoulomb
 * FC
 * (i) Fire Control
 * Football Club
 * (s) Funnel Cloud (METAR Code)
 * FCA
 * (i) Fellowship of Christian Athletes
 * Fiat Chrysler Automobiles
 * Fraction of Combat Active forces
 * FCC – (i) U.S. Federal Communications Commission
 * FCE – (i) First Certificate in English
 * FCF – (i) Financial Free Cash Flow
 * FCFS – (i) First Come, First Served
 * FCLA – Fraud Claims Law Associate
 * FCM
 * (i) Federation of Canadian Municipalities
 * Fogarty's Cove Music
 * FCO – (i) UK Foreign and Commonwealth Office
 * FCS
 * (i) Football Championship Subdivision (U.S. college football)
 * Future Combat System
 * FCSB – (i) Fotbal Club Steaua București, a name claimed by two association football clubs in Bucharest – FCSB and CSA Steaua București
 * FCW – (i) Florida Championship Wrestling
 * FCW - Forward Collision Warning, see Collision avoidance system
 * FCZ – (i) Forward Combat Zone

FD

 * FD – (i) Falun Dafa
 * FDA – (i) Food and Drug Administration (U.S.)
 * FDBK – (i) Feedback
 * FDC
 * (i) Federal Detention Center (U.S.)
 * Fire Direction Centre
 * FDDI – (i) Fibre Distributed Data Interface
 * FdI – (i) Fratelli d'Italia (Italian, "Brothers of Italy"), an Italian political party
 * FDI
 * (i) Fault detection and isolation
 * Films Division of India, a government film production agency
 * Flexible Display Interface
 * Foreign direct investment
 * Frégate de défense et d'intervention (French, "Defense and Intervention Frigate"), a planned class of French Navy ships
 * FDR
 * (i) Flight data recorder
 * Franklin Delano Roosevelt

FE

 * Fe – (s) Iron (Latin Ferrum)
 * FE – (i) Fully Exposed (armoured vehicle target, as opposed to Hull-Down)
 * FEAR
 * (a) First Encounter Assault Recon
 * False Evidence Appears Real
 * Focus sash Endeavor (Quick) Attack Rattata (or F***ing Evil Annoying Rodent, a last-resort tactic in competitive Pokemon battling)
 * FEAST – (a/i) Forum for European-Australian Science and Technology Cooperation
 * FEATS – (a) Festival of European Anglophone Theatrical Societies
 * FEB
 * (i) Federación Española de Baloncesto (Spanish, "Spanish Basketball Federation")
 * Federatie Eredivisie Basketball (Dutch, "Federation Honorary Division (of) Basketball"), the former name of the basketball competition later known in Dutch by the English-language Dutch Basketball League
 * Força Expedicionária Brasileira (Portuguese, "Brazilian Expeditionary Force")
 * FEBA – (a) Forward Edge of the Battle Area
 * fec. – (p) fecit (Latin, "he made it")
 * FED – (a/i) Field emission display
 * FEDEP – (p) Federation Development Process (Simulation)
 * FEF – (i) Frontal Eye Field (neurophysiology)
 * FEI – (i) Fédération équestre internationale (French, "International Federation for Equestrian Sports")
 * FEMA
 * (a/i) Farm Equipment Manufacturers Association
 * (a/i) U.S. Federal Emergency Management Agency
 * Fire Equipment Manufacturers' Association
 * FEMEXFUT – (p) Federación Mexicana de Fútbol Asociación (Spanish, "Mexican Association Football Federation")
 * FENAFUTH – (p) Federación Nacional Autónoma de Fútbol de Honduras (Spanish, "National Autonomous Football Federation of Honduras")
 * FENS – (a/i) Federation of European Neuroscience Societies
 * FEP – (i) Firepower Enhancement Program – Fleet satellite (FLTSAT) Extremely high frequency (EHF) Package
 * FEPAFUT – (p) Federación Panameña de Fútbol (Spanish, "Panamanian Football Federation")
 * FES – (i) Flywheel Energy Storage
 * FEST – (a) Frankfurt English Speaking Theatre
 * FET – (a) Field-effect transistor
 * FEZ – (a/i) Fighter Engagement Zone

FF

 * ff – (s) Fula language (ISO 639-1 code)
 * fF – (s) Femtofarad
 * FF
 * (i) Final Fantasy
 * (p) Firefox (Web browser)
 * FFA
 * (i) Football Federation Australia, former name of the governing body now known as Football Australia
 * Pacific Islands Forum Fisheries Agency
 * Free-Fire Area
 * Fusiform Face Area
 * Future Farmers of America (today the National FFA Organization)
 * FFB – (i) Frum From Birth (referring to an observant Jew born into a religiously observant family)
 * FFC – (i) Free For Chat
 * FFCM — Fellow of the Faculty of Community Medicine (fellowship created in 1972, now replaced by FFPH)
 * FFE – (i) Fukuoka Futures Exchange
 * FFF – (i) Fédération française de football (French, "French Football Federation")
 * FFG – (s) Guided Missile Frigate (hull classification symbol)
 * FFOV – (i) Forward Field Of View
 * FFP - (i) Federally Funded Participation
 * FFPH — Fellow of the Faculty of Public Health, replacing FFPHM
 * FFR – (i) Fédération française de rugby (French, "French Rugby (Union) Federation")
 * FFS – (i) For Fuck's Sake
 * FFT
 * (i) Fast Fourier transform
 * Final Fantasy Tactics

FG

 * FG – (i) Falun Gong
 * fg – (s) Femtogram
 * FG – (s) Fog (METAR Code) – French Guiana (FIPS 10-4 territory code)
 * FGR – (a) Flickr Group Roulette

FH

 * fH – (s) Femtohenry
 * FHFIF – (i) Foster's Home for Imaginary Friends
 * FHI – (i) Family Health International, Fuji Heavy Industries, Ltd.

FI

 * fi – (s) Finnish language (ISO 639-1 code)
 * FI – (s) Finland (ISO 3166 digram; FIPS 10-4 country code)
 * FIA – (a) Fédération internationale de l'automobile (French "International Automobile Federation")
 * FIAT – (a) Fabbrica Italiana Automobili Torino (Italian "Italian Car Factory of Turin")
 * FIB – (a) Fucking Illinois Bastard (Wisconsin slang, variants exist)
 * FIBA – originally (a) Fédération internationale de basket-ball amateur (French, "International Amateur Basketball Federation"); since 1989, (p) Fédération internationale de basket-ball
 * FIBUA – (i/a) Fighting In Built-Up Areas
 * FIC – (i) Fellowship for Intentional Community
 * FID – (i) Foreign Internal Defence
 * FIDÉ – (a) Fédération internationale des échecs (French, "World Chess Federation")
 * FIE – (i) Fly-In Echelon
 * FIFA – (a) Fédération internationale de football association (French, "International Association Football Federation")
 * FIFe – (a) Fédération internationale féline (French, "International Feline Federation")
 * FIFO – (a) First In, First Out
 * FIFRA – (a) Federal Insecticide, Fungicide, and Rodenticide Act
 * FIG
 * (i) Fédération internationale des géomètres (French, "International Federation of Surveyors")
 * Fédération internationale de gymnastique (French, "International Federation of Gymnastics")
 * Feminist Improvising Group (music ensemble)
 * FIGJAM – (a) Fuck I'm Good, Just Ask Me
 * fij – (s) Fijian language (ISO 639-2 code)
 * FILA – (a) Fédération internationale des luttes associées (French, "International Federation of Associated Wrestling Styles"), former name of the sport governing body now known as United World Wrestling
 * FILO – (a) First In, Last Out (see also LIFO)
 * FIMPT – (i) Fellow of the Institute of Maxillofacial Prosthetists and Technologists
 * fin – (s) Finnish language (ISO 639-2 code)
 * FIN – (s) Finland (ISO 3166 trigram)
 * FINA – (p/a) Fédération internationale de natation (French, "International Swimming Federation")
 * FIPS – (a) Federal Information Processing Standard
 * FIR
 * (i) Final Inspection Report
 * Federazione Italiana Rugby (Italian, "Italian Rugby (Union) Federation")
 * FIRES – Fever Induced Refractory Epilepsy Syndrome or Febrile Infection-Related Epilepsy Syndrome
 * FIS – (a/i) Fédération internationale de ski (French "International Ski Federation")
 * FISA – (a) Fédération Internationale des Sociétés d'Aviron (French, "International Federation of Rowing Associations")
 * FISH – (a) Fluorescence In-Situ Hybridisation
 * FiST – (p) Fire Support Team
 * FITS – (a) Flexible Image Transport System
 * FIU – (i) Florida International University

FJ

 * fj – (s) Fijian language (ISO 639-1 code)
 * fJ – (s) Femtojoule
 * FJ – (s) Fiji (ISO 3166 digram; FIPS 10-4 country code)
 * FJD – (s) Fiji dollar (ISO 4217 currency code)
 * FJI – (s) Fiji (ISO 3166 trigram)
 * FJN – (a) Financial Job Network

FK

 * fK – (s) Femtokelvin
 * FK – (s) Falkland Islands (ISO 3166 digram; FIPS 10-4 territory code)
 * f.k.a. or F/K/A – (i) Formerly Known As
 * FKP – (s) Falkland Islands pound (ISO 4217 currency code)
 * FKSM – (i) Fort Knox Supplemental Manual
 * FKT – (i) Fastest Known Time

FL

 * fl – (p) floruit (Latin, "living") (genealogy)
 * fL – (s) Femtolitre
 * FL – (s) Florida (postal symbol)
 * FLA – (p) Florida – (i) Front Line Assembly – Future Large Aircraft
 * FLAC – (a/i) Free Lossless Audio Codec
 * FLAC – (a/i) Free Legal Advice Centres
 * FLAK – (p) FLugAbwehrKanone (German for "Anti-Aircraft Guns")
 * FLB – (i) Forward Logistics Base
 * FLET – (a/i) Forward Line of Enemy Troops
 * FLG – (p) Falun Gong
 * FLIP – (p) Flight Information Publication
 * FLIR – (i) Forward Looking InfraRed (sensor)
 * FLK – (s) Falkland Islands (ISO 3166 trigram)
 * Also Funny-Looking Kid, a medical initialism for a young child with a mostly normal but somewhat unusual ("funny") appearance that raises the suspicion index for congenital disorder. Used only before a medical diagnosis has determined the cause of the unusual appearance.
 * FLOT – (a/i) Forward Line of Own Troops
 * FLSA – (i) Fair Labor Standards Act
 * FLQ – (i) Front de libération du Québec (French for "Québec Liberation Front")
 * FLQ – (a) Free Legal Questions
 * FLTSAT – (p) Fleet Satellite
 * FLTSATCOM – (p) Fleet Satellite Communication System
 * FLUBOS – (a) Fat, Lazy, Useless, Bag Of Shit

FM

 * FM – (s) Factory Mutual http://fmglobal.com
 * fm – (s) Femtometre
 * Fm – (s) Fermium
 * FM
 * (i) Federal Magistrate (Australian post-nominal)
 * (s) Federated States of Micronesia (postal symbol; ISO 3166 digram; FIPS 10-4 territory code)
 * (i) Field Manual
 * Flight Manager
 * Frequency Modulation (electronics)
 * FMC
 * (i) Federal Magistrates' Court (an Australian federal court, formerly FMS)
 * Food Machinery Corporation (original name of the company now known as FMC Corporation)
 * FMCA – (i) Federal Magistrates' Court of Australia (used for citing decisions of the FMC other than family law decisions)
 * FMCAfam – (i) Federal Magistrates' Court of Australia: family (used for citing family law decisions of the FMC)
 * FME – (i) Formal Methods Europe
 * FMECA – (i) Failure Modes and Effect Criticality Analysis
 * FMJD – (i) Fédération Mondiale du Jeu de Dames
 * FMLA – (i) Family Medical Leave Act
 * Fmr – Former (as in "Fmr. president")
 * fMRI – (i) Functional Magnetic Resonance Imaging
 * FMS
 * (i) Federal Magistrates Service (an Australian federal court, now FMC)
 * (i) Flight Management System
 * Foreign Military Sales
 * FMSF – (i) False Memory Syndrome Foundation
 * FMTV – (i) Family of Medium Tactical Vehicles
 * FMCG – (i) Fast-Moving Consumer Goods

FN

 * fN – (s) Femtonewton
 * Fabrique Nationale (Belgian firearms manufacturer)
 * FNA – (i) Functional Needs Analysis
 * FNaF - (a) Five Nights at Freddy’s (horror video game series)

FO

 * fo – (s) Faroese language (ISO 639-1 code)
 * FO
 * (s) Faroe Islands (ISO 3166 digram; FIPS 10-4 territory code)
 * (i) Force Operations (military)
 * Forward Observer
 * Frame Optional (military symbology)
 * FOAD – (a) Fuck Off And Die
 * FOAF – (a) Friend Of A friend
 * FoB – (i) Free On Board (shipping)
 * FOB – (i/a) Forward Operating Base
 * FOC
 * (i) First of Class
 * Forward of center (measure of weight bias of an arrow)
 * Full Operational Capability
 * FOD - Foreign Object Debris
 * FoE
 * (a/p) Federation of Earth
 * (p) Friends of the Earth
 * FOGC – (i) Federal Oil and Gas Council
 * FOH – (a) Front Of House
 * FOIA – (a) Freedom of Information Act
 * FOM – (a) Federation Object Model
 * FOMO – (a) Fear of missing out
 * FONSI – (a) Finding of No Significant Impact
 * FOO – (a) Forward Observation Officer
 * FOR
 * (i) Field Of Regard
 * Frame Of Reference
 * Fortran – (p) The IBM Mathematical FORmula TRANslating System (programming language)
 * FOS
 * (i) Florida Ornithological Society
 * Full Operational Status
 * FoS – (i) Family of Systems
 * FOSE – (p) Fallout 3 Script Extender
 * FOSE – (a) Federal Office Systems Expo
 * FOT – (i) Free on truck
 * FOTA – (i) Fellow of the Orthodontic Technicians Association
 * FOTC – Flight of the Conchords
 * FOUO – (i) For Official Use Only
 * FOV – (i) Field Of View

FP

 * FP – (s) French Polynesia (FIPS 10-4 territory code)
 * FPF
 * (i) Federação Portuguesa de Futebol ("Portuguese Football Federation" in that language)
 * Final Protective Fire
 * fps – (s) frames per second (motion pictures, television, computer graphics)
 * FPS
 * (i) Fire Prevention System
 * First-person shooter (computer/video games)
 * FOOP – (s) Friends Of Organ Pipes (Volunteer group)

FQ

 * FQ – (s) Baker Island (FIPS 10-4 territory code) – French Southern and Antarctic Territories (ISO 3166 digram; obsolete 1979)
 * FQDN – (i) Fully Qualified Domain Name

FR

 * fr – (i) For real
 * fr – (s) French language (ISO 639-1 code)
 * Fr – (s) Francium
 * FR – (s) France (FIPS 10-4 country code; ISO 3166 digram)
 * fra – (s) French language (ISO 639-2 code)
 * FRA
 * (i) Federal Railroad Administration
 * (s) France (ISO 3166 trigram)
 * FRAGO – (p) Fragmentary Order (military)
 * FRAND – (a) Fair, reasonable, and non-discriminatory (concept in standards-setting and intellectual property law)
 * FRCP
 * (i) Federal Rules of Civil Procedure
 * Fellow of the Royal College of Physicians
 * FRICBM – (i) Full Range ICBM
 * frr – (s) North Frisian language (ISO 639-2 code)
 * FRR
 * (s) Falls Road Railroad (reporting mark)
 * (i) Federaţia Română de Radioamatorism (Romanian, "Romanian Amateur Radio Federation")
 * (i) Fix, Rebuild, Replace
 * Federaţia Română de Rugby (Romanian, "Romanian Rugby (Union) Federation")
 * FRO – (s) Faroe Islands (ISO 3166 trigram)
 * FRS
 * (i) Fellow of the Royal Society
 * U.S. Federal Reserve System
 * FRSA – (i) Fellow of the Royal Society of Art
 * FRSL – (i) Fellow of the Royal Society of Literature
 * fry – (s) West Frisian language (ISO 639-2 code)
 * FRY – (i) Federal Republic of Yugoslavia

FS

 * fs – (s) Femtosecond
 * fS – (s) Femtosiemens
 * FS
 * (i) Fire Support (military)
 * (s) French Southern and Antarctic Territories (FIPS 10-4 territory code)
 * FSA
 * (i) Fire Support Area
 * UK Food Standards Agency
 * Functional Solution Analysis
 * FSB
 * (i) Federal'naya Sluzhba Bezopasnosti Rossiyskoi Federatsii (Федера́льная слу́жба безопа́сности Росси́йской Федера́ции, Russian "Federal Security Service of the Russian Federation", succeeded the FSK in 1995)
 * Forward Support Battalion
 * FSC
 * (i) Federal Supply Classification
 * (a) Forest Stewardship Council (ecological pressure group
 * FSCL – (i) Fire Support Co-ordination Line
 * FSE – (i) Fire Support Element
 * F&SF – (i) (The Magazine of) Fantasy & Science Fiction
 * FSF – (i) Free Software Foundation
 * FSH – (i) Follicle-stimulating hormone
 * FSI – (i) Fuel Stratified Injection
 * FSK – (i) Federal'naya Sluzhba Kontrrazvedki (Федера́льная Слу́жба Контрразве́дки, Russian "Federal Counterintelligence Service", succeeded the KGB in 1991)
 * FSM
 * (s) Federated States of Micronesia (ISO 3166 trigram)
 * (i) Flying Spaghetti Monster (satirical religion)
 * FSO
 * (i) Fire Support Officer
 * Flotilla Staff Officer
 * Foreign Service Officer
 * FSS – (i) Fire Support Station
 * FSSP – (i) Families of Structurally Similar Proteins
 * FST
 * (i) Finance Support Team
 * Finlands Svenska Television (Finland's Swedish-language television)
 * Future Soviet Tank (Cold War era)
 * FSTC – (i) Foreign Science Technology Center (now NGIC)
 * FSV
 * (i) Fire Support Vehicle
 * Fisheries Survey Vessel
 * Flexible Sender Validation
 * Fort St. Vrain
 * Fußball und Sportverein (German "Football and Sport Association", as in FSV Mainz)

FT

 * fT – (s) Femtotesla
 * FTC – (i) Federal Trade Commission
 * FTE – (i) Full Time Equivalent
 * FTHGOAC - For The Highest Good Of All Concerned
 * FTL – (i) Faster Than Light
 * FTP – (i) File Transfer Protocol
 * FTS
 * (i) Flight Termination System used during some rocket launches
 * Follow-the-sun
 * Fuck That Shit
 * FTSE – (a/i) Financial Times Stock Exchange ("footsie")
 * FTW – (i) For The Win (a commonly used phrase used online to indicate success), Fuck the World, Forever Together Wherever (gang slogan)

FU

 * FU – (s) Smoke (METAR Code)
 * FUBAR – (a) Fucked/Fouled Up Beyond All Recognition/Repair
 * f/u/b/o – (i) For the use and benefit of (found in legal documents)
 * FUBU - (a) For Us, By Us
 * FUCK – (a) For, Unlawful, Carnal, Knowledge (Van Halen album title)
 * FUD – (a) Fear, Uncertainty & Doubt (marketing strategy)
 * FUGAZI (acronym) – (a) British/American Army slang, then Video Gamer FPS slang for Fucked Up, Got Ambushed, Zipped In.
 * ful – (s) Fula language (ISO 639-2 code)

FV

 * fV – (s) Femtovolt

FW

 * fW – (s) Femtowatt
 * FW – (s) Forward
 * F/W – (i) Fixed Wing
 * FWC – (i) Football World Cup
 * FWD - (a) Front Wheel Drive (automobile transmission type)
 * FWF – (i) Fixed Word Format
 * FWI – (i) French West Indies
 * FWIW – (i) For What It's Worth
 * FWS – (i) U.S. Fish and Wildlife Service
 * FWT – (i) Fresh Water Tank

FX

 * FX – (a) Firefox – Fox Extended – (s) Metropolitan France (ISO 3166 digram; obsolete 1997) – Special effect
 * FXX – (s) Metropolitan France (ISO 3166 trigram; obsolete 1997)

FY

 * fy – (s) West Frisian language (ISO 639-1 code)
 * FY – (i) Fiscal Year – (s) Former Yugoslav Republic of Macedonia (NATO country code)
 * FYA – (i) For Your Agenda
 * FYDP – (i) Five-Year Defense Plan (U.S.)
 * FYI – (i) For Your Information
 * FYI&A – (i) For Your Information and Action
 * FYROM – (a) Former Yugoslav Republic of Macedonia, currently North Macedonia

FZ

 * FZDZ – (s) Freezing Drizzle (METAR Code)
 * FZFG – (s) Freezing Fog (METAR Code)
 * FZRA – (s) Freezing Rain (METAR Code)