H2

**H2**, **H02**, or **H-2** may refer to:

## Arts and media

- Armenia 2 (H2), a private television company broadcasting in Armenia and Nagorno-Karabakh
- H2 (TV channel), the rebranded name of the former channel _History International_
- _H2_ (manga), a baseball manga by Mitsuru Adachi
- _Halo 2_, a video game for the Xbox, created and developed by Bungie
- _Halloween II_ (2009 film), initially abbreviated to _H2_
- _Hollywood Squares_, referred to as _H<sup>2</sup>_ informally during the 2002-2004 seasons

## Computing

- , level 2 heading markup for HTML Web pages, see HTML element#heading
- H2 (DBMS), an open-source Java SQL database-management system
- DSC-H2, a 2006 Sony Cyber-shot H series camera
- HTTP/2, major revision of HTTP, often abbreviated in discussions as h2, and identifying itself to other servers as h2 in TLS negotiation or h2c in the HTTP Upgrade header
- LGA 1155 CPU socket, also known as Socket H2

## Roads and transportation

- Interstate H-2, a highway in Hawaii, located on the island of Oahu
- London Buses route H2

### Biology and medicine

- H02, a code for "Other inflammation of eyelid" in ICD-10 Chapter VII: Diseases of the eye, adnexa
- ATC code H02 _Corticosteroids for systemic use_, a subgroup of the Anatomical Therapeutic Chemical Classification System
- British NVC community H2, a heath community in the British National Vegetation Classification system
- Histamine H<sub>2</sub> receptor
- Prostaglandin H2
- H-2, the Major histocompatibility complex of the mouse (equivalent of the Human Leukocyte Antigens)
- or , wide- or narrow-sense heritability

### Chemistry

- H<sub>2</sub>, the chemical formula for hydrogen gas (Dihydrogen)
- Hydrogen-2, H-2, <sup>2</sup>H (called deuterium), the isotope of hydrogen with one proton, one neutron, and one electron

### Other uses in science and mathematics

- H II region, a region of interstellar atomic hydrogen that is ionized
- , one of the three laryngeals in the reconstructed Proto-Indo-European language
- The Hardy space H<sup>2</sup>

### Air and space

- H-II, a family of Japanese liquid-fueled rockets
    - H-IIA
    - H-IIB
    - H-II Transfer Vehicle, a Japan Aerospace Exploration Agency unmanned spacecraft
- H-2 MUPSOW, a precision-guided glide bomb manufactured by Pakistan
- Landgraf H-2, an American single-seat twin-rotor helicopter produced in 1944
- Standard H-2, a U.S. Army reconnaissance plane produced in 1916

### Rail

- LB&SCR H2 class, a British LB&SCR locomotive
- H02 locomotive (Germany), a high-pressure steam locomotive made in 1930
- Saxon XII H2, a German steam locomotive produced in 1922
- PRR H2, a model within the American PRR locomotive classification
- H2, designation for METRORail Siemens S70 light rail vehicles

### Road

- Hummer H2, a car model
- Kawasaki H2 Mach IV, 1970s two-stroke motorcycle
- Kawasaki Ninja H2, 2010s supercharged motorcycle

### Sea

- HMAS _Success_ (H02), a Royal Australian Navy Admiralty S-class destroyer completed in 1918
- HMS _Exmouth_ (H02), a British Royal Navy E-class destroyer commissioned in 1934
- HMS _H2_, a British Royal Navy H class submarine commissioned in 1915
- USS _H-2_ (SS-29), a U.S. Navy H-class submarine commissioned in 1913

## Other uses

- H-2A Visa, a United States visa for temporary or seasonal agricultural work
- H2, the second half of the business year
- H2 lamp, a halogen vehicle headlamp no longer manufactured
- H2, a model of hurricane tie manufactured by Simpson Strong-Tie Co.
- Sky Airline (IATA code H2)
- Area H2, an Israeli-controlled area under the Hebron Protocol