List of acronyms: H. (Main list of acronyms)


 h – (s) Hecto
 H – (s) Henry – Hydrogen

HA
 ha – (s) Hausa language (ISO 639-1 code) – Hectare
 HA – (s) Haiti (FIPS 10-4 country code) – (i) High Availability
 HAARP – (a) High Frequency Active Auroral Research Program
 HAART – (a) Highly Active Anti-Retroviral Therapy
 HAI – (i) Human Awareness Institute
 HAL – (i) Hardware Abstraction Layer
 HALO –
 (a) Habitation and Logistics Outpost (of the planned Lunar Gateway space station)
 High Altitude Low Opening (parachute jump)
 HALT
 (a) Highly Accelerated Life Test
 (a) Hungry Angry Lonely Tired
 HAMR – (a) Heat-assisted magnetic recording
 HAN - (s) IATA code for Noi Bai International Airport
 HANS – (a) Head And Neck Support (device used in many race cars)
 HARM – (a) High-speed Anti-Radiation Missile
 hat – (s) Haitian Creole language (ISO 639-2 code)
 HAT – (i/a) Highest Astronomical Tide (nautical charts) – (a) Hungarian Automated Telescope
 hau – (s) Hausa language (ISO 639-2 code)
 HAW – (i) Heavy Antitank Weapon
 HAWK – (a) Homing All the Way Killer (air defence system)
 HAZ – (i) Heat-Affected Zone
 HAZMAT – (p) Hazardous Materials

HB
 HBCD – (p) HexaBromoCycloDodecane
 HBCI – (i) Home Banking Computer Interface
 HBCU – (i) Historically black colleges and universities (U.S.)
 HBO – (i) Home Box Office
 HBR – (i) Harvard Business Review
 HBT – (i) Heterojunction Bipolar Transistor
 HBV – (i) Hepatitis B Virus

HC
 h.c. – (i) honoris causa (Latin, "for the sake of honor")
 HCAL — (p) Homogeneous calorimeter
 HCCI – (i) Homogeneous Charge Compression Ignition
 HCF – (i) Highest Common Factor
 HCI – (i) Human–Computer Interaction/Interface
 HCPCS – (i) Health Care Procedure Coding System
 HCSC – (i) Higher Command and Staff Course
 HCT – (i) Higher Colleges of Technology, tertiary education institution in the United Arab Emirates (UAE)

HD
 HD
 (i) Henry Draper (star catalogue)
 Hull-Down (armored vehicle target, as opposed to Fully Exposed)
 High Definition
 Huntington's Disease
 HDD
 (i) Hard Disk Drive
 High-Density Disk
 HDL – (i) High-Density Lipoprotein
 HDM – (i) Human Decision-Making
 HDMI – High-Definition Multimedia Interface
 HDR
 (i) Hard disk recorder
 Henningson, Durham & Richardson (founders of the engineering and construction firm now known by their initials)
 High dynamic range, a term used in both digital imaging and 3D rendering
 Hot Dry Rock (experimental geothermal technology)
 Human Development Report (UN publication)
 HDRA – (i) Henry Doubleday Research Association
 HDTV – (p) High-definition television

HE
 he – (s) Hebrew language (ISO 639-1 code)
 He – (s) Helium
 HE – (a) High Explosive
 HEAT – (a) High-Explosive Anti-Tank (ammunition)
 heb – (s) Hebrew language (ISO 639-2 code)
 HEBA – (p) Hellenic Basketball Clubs Association
 HEER – (a) High-Explosive Extended Range (ammunition)
 HEIC – (i) Honourable East India Company
 HELOC – (a) Home equity line of credit
 HEMP – (a) High-Altitude Electromagnetic Pulse
 HEO
 (a) High Earth orbit
 (a) Highly elliptical orbit
 HEOSS – (a) High Earth Orbit Space Surveillance
 HEP – (i) High-Explosive Plastic (ammunition)
 HEPA – (a/i) High-Efficiency Particulate Air (filter)
 her – (s) Herero language (ISO 639-2 code)
 HESH – (a) High-Explosive, Squash-Head (ammunition)
 HESV – (i) Heavy Engineering Support Vehicle
 HETT – (a) Heavy Equipment Transporting Truck / Heavy Equipment Truck Tractor
 HEU – (i) Highly Enriched Uranium
 HEV
 Hybrid Electric Vehicle (non-rechargeable)
 Hazadous EnVironment suit - outfit worn by Half-Life protagonist Gordon Freeman
 Hewitts – (a) Hills in England, Wales and Ireland over Two Thousand feet (with topographic prominence of at least 30 m)

HF
 Hf – (s) Hafnium
 HF – (i) High Frequency
 HFAC – (p) Human Factors ("aytchfak")
 HFE – (i) Human Fertilisation and Embryology (UK Act)
 HFE – (s) The common-emitter current gain in a BJT transistor (also represented by βF).  See: BJT
 HFEA – (i) Human Fertilisation and Embryology Authority (UK)

HG
 Hg – (i) Mercury (Latin Hydrargyrum)
 HGC – (i) UK Human Genetics Commission
 HGF – (i) Human Growth Factor
 HGTV – (i) Home & Garden Television

HH
 HHD – (p) humanitatum doctor (Latin, "doctor of humanities")
 HHB – Ha Ha Bonk – The noise made when you laugh your head off. Used instead of LOL...
 HHS – (i) (U.S. Department of) Health and Human Services

HI
 hi – (s) Hindi language (ISO 639-1 code)
 HI – (s) Hawaii (postal symbol)
 HIC – Hierarchical Ingredient Code, a system of classifying drug ingredients 
 HIDACZ – (p) High-Density Airspace Control Zone ("high dak zed/zee")
 HIH – (i) His (or Her) Imperial Highness
 HIIT - (a) High-Intensity Interval Training
 HIM – (i) His (or Her) Imperial Majesty
 HIMAD – (p) High to Medium Altitude Air Defence (see also H/MAD)
 HIMARS - (a) HIgh Mobility Artillery Rocket System
 HIMEZ – (a) High Altitude Missile Engagement Zone
 HIMYM – How I Met Your Mother
 hin – (s) Hindi language (ISO 639-2 code)
 HIPAA – (i) U.S. Health Insurance Portability and Accountability Act
 Hipparcos – (p) HIgh Precision Parallax COllecting Satellite
 Hird – (a) Hurd of interfaces representing depth (cf. HURD)
 HiRISE – (p) High Resolution Imaging Science Experiment
 HIT – (a) Health Information Technology
 HIV – (i) Human Immunodeficiency Virus
 HIWT – (i) Hobart Institute of Welding Technology

HJ
 HJ – (i) hic jacet (Latin, "here lies")
 HJD – (i) Heliocentric Julian Day

HK
 HK – (s) Hong Kong (ISO 3166 digram; FIPS 10-4 territory code)
 HKD – (s) Hong Kong dollar (ISO 4217 currency code)
 HKG – 
(s) Hong Kong (ISO 3166 trigram)
 Hong Kong International Airport (IATA code)
 HKMAO – (i) Hong Kong and Macau Affairs Office
 HKO – (i) Hong Kong Observatory
 HKS – (i) HyperKinetic Syndrome
 HKSAR – (i) Hong Kong Special Administrative Region of the People's Republic of China

HL
 hL – (s) Hectolitre
 HL
 (i) Holding Line
 (i) Half-Life
 HLA – (i) High Level Architecture (simulation) – Human Leukocyte Antigen
 HLL – (i) High-Level Language
 HLN – (i) Headline News
 HLOS – (i) High Level Output Specification
 HLS – (i) hoc loco situs (Latin, "laid in this place")
 HLVW – (i) Heavy Logistics Vehicle, Wheeled

HM
 HM 
 (s) Heard Island and McDonald Islands (ISO 3166 digram; FIPS 10-4 territory code)
 (i) His Majesty / Her Majesty (title for certain monarchs)
 H/MAD – (p) High/Medium Altitude Air Defence ("aytchmad"; see also HIMAD)
 HMCE – (i) Her/His Majesty's Customs and Excise (former UK government department; succeeded by HM Revenue and Customs)
 HMCS
 (i) Her/His Majesty's Canadian Ship
 Her Majesty's Courts Service (former UK agency; succeeded by Her Majesty's Courts and Tribunals Service)
 HMD
 (s) Heard and McDonald Islands (ISO 3166 trigram)
 (i) Helmet-Mounted Display
 HMF – (p) HydroxyMethyl Furfural
 HMICFRS - (i) His/Her Majesty's Inspectorate of Constabularies and of Fire and Rescue Services (UK Government agency)
 HMM – (i) Hidden Markov model
 HMMWV – (i) High Mobility Multipurpose Wheeled Vehicle ("hum-vee"; "hummer")
 hmo – (s) Hiri Motu language (ISO 639-2 code)
 HMO – (i) Health maintenance organization
 HMO – (i) House in multiple occupation
 HMO – (i) Human milk oligosaccharide
 HMP – (i) Her Majesty's Prison
 HMRC – (i) Her/His Majesty's Revenue and Customs
 HMS - (i) Her/His Majesty's Ship (Royal Navy)
 HMSO – (i) Her Majesty's Stationery Office
 HMV – (i) His Master's Voice

HN
 HN – (s) Honduras (ISO 3166 digram)
 HND
 (s) Honduras (ISO 3166 trigram)
 Tokyo Haneda Airport (IATA code)
 HNL 
 (s) Honduran lempira (ISO 4217 currency code)
 Daniel K. Inouye International Airport (IATA code)

HO
 ho – (s) Hiri Motu language (ISO 639-1 code)
 Ho – (s) Holmium
 HO – (s) Honduras (FIPS 10-4 country code)
 HOLLAND – (a) Hope Our Love Lasts And Never Dies
 HOMES – the Great Lakes; Huron, Ontario, Michigan, Erie, Superior
 HONY – Humans of New York, a photoblog. 
 HOPI – (a) Hybrid Optical and Packet Infrastructure (see Internet2, Abilene Network)
 HoReCa – (a) Hotel, Restaurant and Catering
 HORIZON – (p) Hélicoptère d'observation radar et d'investigation sur zone (French, Zone Investigation and Radar Observation Helicopter)
 HOSTAC – (a) Helicopter Operations from Ships Other Than Aircraft Carriers
 HOT – (a) Highly Optimised Tolerance
 HOTAS – (a) Hands on throttle-and-stick
 HOTT or HotT – (i) Hordes of the Things (miniature fantasy wargaming rules; a play on The Lord of the Rings)
 HOV – (i) High Occupancy Vehicle

HP
 hp – (s) horse power
 HP –
(i) Hewlett-Packard
Hindustan Petroleum
(s) Himachal Pradesh (Indian state code)
 HPA – (i) UK Health Protection Agency
 HPCL – (i) Hindustan Petroleum Corporation Limited
 HPGL or HP-GL – (i) Hewlett-Packard Graphics Language
 HPH - (s) IATA code for Cat Bi International Airport
 HP-IB – (i) Hewlett-Packard Instrument/Interface Bus (first implementation of GP-IB, later standardised and now known as IEEE-488)
 HP-IL – (i) Hewlett-Packard Interface Loop (serial bus used with some HP calculators and computers, notably the HP-41 and HP-71 series)
 HPLC – (i) High Performance Liquid Chromatography
 HPMOR – (i) Harry Potter and the Methods of Rationality (work of Harry Potter fan fiction)
 HPT – (i) High[er] Payoff Target
 HPV – (i) Human Papilloma Virus

HQ
 HQ –
(i) Headquarters
(s) Howland Island (FIPS 10-4 territory code)
 HQ – (i) High Quality 
 HQDA – (i) Headquarters, Department of the Army

HR
 hr – (s) Croatian language (ISO 639-1 code)
 HR
 (s) Croatia (FIPS 10-4 country code; ISO 3166 digram – from the country's native name of Hrvatska)
(s) Haryana (Indian state code)
 (i) Harvard Revised star catalogue
 Human Resources
 HRBL – (i) High-level Representation of Behavior Language (original name of the Herbal language)
 HRD – (i) Human Resource Development
 HRED – (i) (U.S. Army Research Laboratory's) Human Research and Engineering Directorate (Aberdeen Proving Ground, Maryland)
 HRF – (i) High Readiness Forces
 HRH – (i) His (or Her) Royal Highness
 HRK – (s) Croatian kuna (ISO 4217 currency code)
 HRM – (i) His (or Her) Royal Majesty
 HRM – (i) Human Resource Management
 HRT – (i) Hormone Replacement Therapy
 hrv – (s) Croatian language (ISO 639-2 code)
 HRV
 (s) Croatia (ISO 3166 trigram)
 (i) High Resolution Visible

HS
 Hs – (s) Hassium
  HSA – A health savings account available to taxpayers in the United States.
 HSBC – (i) The Hong Kong and Shanghai Banking Corporation
 HSC
 (i) Higher School Certificate
 (i) Helicopter Sea Combat, a type of U.S Navy aviation squadron
 HSM – (i) High School Musical
 HSMAD – (i) Human Science/Modeling and Analysis Data
 HSN – (i) Home Shopping Network
 HSPH – (i) Harvard School of Public Health
 HSS
 (i) Health Service Support
 (i) High-Speed Steel
 HSSI – (i) High-Speed Serial Interface
 HST – see entry
 HSV
 (i) Herpes Simplex Virus
 Hue Saturation Value (colour model)

HT
 ht – (s) Haitian Creole language (ISO 639-1 code)
 HT
 (s) Haiti (ISO 3166 digram)
 (i) High Temperature
 hoc tempore (Latin, "at this time")
 hoc titulo (Latin, "under this title")
 HTA – (i) HyperText Application
 HTC
 High Tech Computer Corporation, original name of the company now known simply as HTC
 HTFU – (a) Harden The F**k Up
 HTG – (s) Haitian gourde (ISO 4217 currency code)
 HTH – (a) Hope That Helps
 HTI – (s) Haiti (ISO 3166 trigram)
 HTML – (i) HyperText Markup Language
 HTS – (i) High-Temperature Superconducting wire
 HTTP – (i) HyperText Transfer Protocol

HU
 hu- (s) Hungarian language (ISO 639-1 code)
 HU – (s) Hungary (ISO 3166 digram; FIPS 10-4 country code)
 HUD – (i/a) Head-Up Display – Housing and Urban Development
 HUF – (s) Hungarian forint (ISO 4217 currency code)
 HUHA – (a) Head up his/her ass (Marine salute; probably a backcronym)
 HUI - (s) IATA code for Hue's Phu Bai International Airport
 HUMINT – (p) Human Intelligence (military parlance)
 Hum-Vee – See HMMWV
 hun – (s) Hungarian language (ISO 639-2 code)
 HUN – (s) Hungary (ISO 3166 trigram)
 HURD – (a) Hird of Unix-Replacing Daemons (cf. Hird)
 HVU – (i) High Value Unit (military)

HV
 HV – (s) Upper Volta (ISO 3166 digram; obsolete 1984)
 HVAC – (s) Heating, ventilation and air conditioning Used in architecture, business and marketing; refers to a building's entire system of heating, moving, or cooling air.
 HVAP – (i) High Velocity Armour Piercing (ammunition)
 HVHF – (i)High velocity human factors
 HVI - (i) High Value Individual
 HVM – (i) High Velocity Missile
 HVO – (s) Upper Volta (ISO 3166 trigram; obsolete 1984)
 HVP –
 (i) HarborView Properties
 High vacuum process
 Hydrolyzed vegetable protein
 High Velocity Protection
 H.V.P. (rapper)
 High Voltage Protection
 High Vapor Pressure
 High-Velocity Projectile
 High-Video Pass
 High-Velocity Particle
 Hub Voice Processor
 Human Variome Project
 HVT - (i) High-Value Target (US military terminology)

HW
 HW – (p) Hardware – (i) High Water (nautical charts)
 HWM – (i) Hardware morphing (computer graphics rendering)

HX
 HX –
 (s) IATA code of Hong Kong Airlines
 (s) Medical history
 (s) Hydrogen halide
 (s) Concept automobile by HUMMER
 HXB – (s) The glycoprotein Tenascian C

HY
 hy – (s) Armenian language (ISO 639-1 code)
 hye – (s) Armenian language (ISO 639-2 code)
 HYP
 (i) Halkın Yükselişi Partisi (Turkish: "People's Ascent Party"), a political party in Turkey
 Harvard, Yale, Princeton (perennially at or near the top of American university rankings)
 HYS – (i) Harvard, Yale, Stanford (perennially named as the top three law schools in the U.S.)

HZ
 hz – (s) Herero language (ISO 639-1 code)
 Hz – (s) Hertz
 HZ – (s) Haze (METAR Code)

Acronyms H