# C2

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/C2
> Markdown URL: https://mediated.wiki/source/C2.md
> Source: https://en.wikipedia.org/wiki/C2
> Source revision: 1355838156
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Self-reference|For the Wikipedia C2 criterion for speedy deletion, see {{slink|Wikipedia:Criteria for speedy deletion#C2}}.}}
{{Wiktionary}}
'''C2''' or a derivative ('''C-2''', '''C<sup>2</sup>''', etc.) may refer to:
{{TOC right}}

==Mathematics and physics==
* ''C''<sub>2</sub>, one of the common notations for the [cyclic group](/source/cyclic_group) of order 2
* ''C''<sup>2</sup> [differentiability class](/source/differentiability_class)
* ''C''<sup>2</sup> or <math>\Complex^2</math>, the [complex coordinate plane](/source/complex_coordinate_plane)
* ''c''<sup>2</sup> the square of the [speed of light](/source/speed_of_light) (in the mass–energy equivalence formula)
* [C2 (space group)](/source/C2_(space_group)), three-dimensional space group number 5

==Biology==
* [C2 domain](/source/C2_domain), a protein structural domain
* [C2 regulatory sequence](/source/C2_regulatory_sequence) for the insulin gene
* [Apolipoprotein C2](/source/Apolipoprotein_C2), a human apolipoprotein
* In human anatomy, C2 may refer to:
** [Cervical vertebra 2](/source/Cervical_vertebra_2), the axis, one of the cervical vertebrae of the vertebral column
** [Cervical spinal nerve 2](/source/Cervical_spinal_nerve_2)
* [Chlorophyll c2](/source/Chlorophyll_c2), a form of chlorophyll
* [Complement component 2](/source/Complement_component_2)
* [Procyanidin C2](/source/Procyanidin_C2), a plant phenolic compound
* [Prodelphinidin C2](/source/Prodelphinidin_C2), a plant phenolic compound
* [Vitamin C2](/source/Vitamin_C2_(disambiguation))
* the ATC code for ''[Antihypertensives](/source/Antihypertensives)'', a subgroup of the Anatomical Therapeutic Chemical Classification System
*C<sub>2</sub> fragments, one of the types of products of [catabolism](/source/catabolism) pathways
* [Haplogroup C-M217](/source/Haplogroup_C-M217), also known as C2, a [Human Y-chromosome DNA haplogroup](/source/Human_Y-chromosome_DNA_haplogroup)

==Chemistry==
* C<sub>2</sub>, [Diatomic carbon](/source/Diatomic_carbon), a molecule made of two carbon atoms
* C2=, [ethylene](/source/ethylene), a two carbon alkene

==Codes or abbreviations==
'''C2''' may be a code or abbreviation for:
* [C<sup>2</sup> Aquarii](/source/C2_Aquarii), a star
* [C<sup>2</sup> Centauri](/source/C2_Centauri), a star
* [C2 (Code Geass)](/source/C2_(Code_Geass)), an anime character
* [C2 explosive](/source/C2_explosive), a form of plastic explosive
* [C2 pylon](/source/C2_pylon), a type of high voltage pylon
* [C2 radio class](/source/C2_radio_class), a class in FM broadcasting in America
* [C2 (classification)](/source/C2_(classification)), a para-cycling classification
* [Group C2](/source/Group_C2), the secondary class of Group C sports car racing
* [Nimrod NRA/C2](/source/Nimrod_NRA%2FC2), a 1982 Group C racing car
* C2, an international standard paper size defined in [ISO 216](/source/ISO_216) (458×648&nbsp;mm)
* C2, a level in the [Common European Framework of Reference for Languages](/source/Common_European_Framework_of_Reference_for_Languages)
* C2, the [NRS social grade](/source/NRS_social_grade) between C1 and D
* C2s, substances listed in [Schedule II of the Controlled Substances Act](/source/Controlled_Substances_Act) in the United States
* [Command and control](/source/Command_and_control), the exercise of authority by a commanding officer over military forces in the accomplishment of a mission
* [Air Luxor](/source/Air_Luxor) IATA airline code
* [C2 Pictures](/source/C2_Pictures), a film company related to Carolco Pictures
* [Bill C-2](/source/Bill_C-2), various legislation of the Parliament of Canada
* C2, or C<sub>2</sub> a note-octave in music, aka [Low C](/source/Low_C)

==Computing==

* C2, a computer security class, defined in the [Trusted Computer System Evaluation Criteria](/source/Trusted_Computer_System_Evaluation_Criteria)
* C2, a bytecode compiler that is part of the [HotSpot](/source/HotSpot) virtual machine implementation
* [C2 (protocol)](/source/C2_(protocol)), a 1985 Commodore file transfer protocol
* [C2 error](/source/C2_error), a read error of a compact disc
* [C2.com](/source/C2.com) or WikiWikiWeb, the first user-editable website
* [C2 (consulting firm)](/source/C2_(consulting_firm)), an initialism for, and {{Abbr|aka|also known as}} Cunningham and Cunningham, a technology consulting firm founded by [Ward Cunningham](/source/Ward_Cunningham)
* [Cryptomeria cipher](/source/Cryptomeria_cipher), a cipher used in digital rights management
* [Command and control (malware)](/source/Botnet)
* [Codec 2](/source/Codec_2), speech compression codec.

==Transportation and space==
* [C2 class Melbourne tram](/source/C2_class_Melbourne_tram)
* [Bavarian C II (Ostbahn)](/source/Bavarian_C_II_(Ostbahn)), an 1862 German steam locomotive
* [Bavarian C II.1](/source/Bavarian_C_II.1), an 1857 German steam locomotive
* [Bavarian C II.2](/source/Bavarian_C_II.2), an 1861 German steam locomotive
* [Chevrolet Corvette (C2)](/source/Chevrolet_Corvette_(C2)), the generation of the Chevrolet Corvette produced between 1962 and 1967
* [Citroën C2](/source/Citro%C3%ABn_C2), a car produced by Citroën in 2004
* [Cluster II (spacecraft)](/source/Cluster_II_(spacecraft)), an ESA space mission
* [Ford C2 platform](/source/Ford_C2_platform), an automobile platform produced by Ford since 2018
* [GNR Class C2](/source/GNR_Class_C2), a British 4-4-2 steam locomotive class
* [LNER Class C2](/source/LNER_Class_C2), classified C1 during GNR ownership 
* [Kawasaki C2](/source/Kawasaki_C2), a bike
* [London Buses route C2](/source/London_Buses_route_C2)
* [LB&SCR C2 class](/source/LB%26SCR_C2_class), an 1893 British 0-6-0 steam locomotive
* [Circumferential Road 2](/source/Circumferential_Road_2) or C-2, an arterial road of Manila, Philippines
* [Saf-T-Liner C2](/source/Saf-T-Liner_C2), a school bus built by Thomas Built Buses
* [Saturn C-2](/source/Saturn_C-2), a 1960 conceptual American launch vehicle
* [Type C2 ship](/source/Type_C2_ship), a type of all-purpose cargo ship
* [C2 (yacht)](/source/C2_(yacht)), a luxury motor yacht
* [Central Circular Route (Shuto Expressway)](/source/Central_Circular_Route_(Shuto_Expressway)) in Tokyo, Japan
* [Mei-Nikan Expressway](/source/Mei-Nikan_Expressway), route C2 in Nagoya, Japan

==Military and aviation==
* [Command and control](/source/Command_and_control), the exercise of authority and direction by a commanding officer
* [C-2 (poison)](/source/C-2_(poison)), developed in the ''Poison laboratory of the Soviet secret services''
* [C2A1](/source/C2A1), Squad Automatic Weapon variant of the FN FAL formerly in Canadian Service
* [ACAZ C.2](/source/ACAZ_C.2), a Belgian prototype fighter aircraft of the 1920s
* [AEG C.II](/source/AEG_C.II), a German World War II armed reconnaissance aircraft
* [Aeronca C-2](/source/Aeronca_C-2), an American airplane
* [AGO C.II](/source/AGO_C.II), a German reconnaissance biplane of World War I
* [Cierva C.2](/source/Cierva_C.2), a 1921 Spanish experimental autogyro 
* [DFW C.II](/source/DFW_C.II), a World War I German reconnaissance aircraft 
* [Fokker C-2](/source/Fokker_C-2), the American military version of the Fokker F.VII aircraft
* [C-2 Greyhound](/source/C-2_Greyhound), the Grumman cargo aircraft of the United States Navy
* {{HMS|C2}}, a British C class submarine of the Royal Navy
* [Kawasaki C-2](/source/Kawasaki_C-2), a military transport aircraft
* [LFG Roland C.II](/source/LFG_Roland_C.II), a 1915 advanced German reconnaissance aircraft
* [LVG C.II](/source/LVG_C.II), a 1910s German two-seat reconnaissance biplane 
* {{USS|C-2|SS-13}}, a C-class submarine of the United States Navy
* {{USS|Charleston|C-2}}, a protected cruiser of the United States Navy

==Other==
* C2, [UEFA Cup Winners' Cup](/source/UEFA_Cup_Winners'_Cup) in football, later merged with UEFA Cup (now [UEFA Europa League](/source/UEFA_Europa_League))
* [C2 Pictures](/source/C2_Pictures), a film studio
* [C-2 visa](/source/C-2_visa), a nonimmigrant visa which allows individuals to travel to and from the headquarters of the United Nations
* [Coca-Cola C2](/source/Coca-Cola_C2), a soft drink launched by The Coca-Cola Company in 2004
* ''[Conduit 2](/source/Conduit_2)'', a 2011 first-person shooter video game
* [AEW Continental Classic](/source/AEW_Continental_Classic), a professional wrestling tournament

==See also==
* [CO2](/source/CO2)
* [CII (disambiguation)](/source/CII_(disambiguation))
* [2C (disambiguation)](/source/2C_(disambiguation))

{{Letter-Number Combination Disambiguation}}

---
Adapted from the Wikipedia article [C2](https://en.wikipedia.org/wiki/C2) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/C2?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.