C2

• C2, one of the common notations for the cyclic group of order 2 • C2 differentiability class • C2 or \Complex^2, the complex coordinate plane • c2 the square of the speed of light (in the mass–energy equivalence formula) • C2 (space group), three-dimensional space group number 5 ==Biology==

• C2 domain, a protein structural domain • C2 regulatory sequence for the insulin gene • Apolipoprotein C2, a human apolipoprotein • In human anatomy, C2 may refer to: • Cervical vertebra 2, the axis, one of the cervical vertebrae of the vertebral column • Cervical spinal nerve 2 • Chlorophyll c2, a form of chlorophyll • Complement component 2 • Procyanidin C2, a plant phenolic compound • Prodelphinidin C2, a plant phenolic compound • Vitamin C2 • the ATC code for Antihypertensives, a subgroup of the Anatomical Therapeutic Chemical Classification System • C2 fragments, one of the types of products of catabolism pathways • Haplogroup C-M217, also known as C2, a Human Y-chromosome DNA haplogroup ==Chemistry==

• C2, Diatomic carbon, a molecule made of two carbon atoms • C2=, ethylene, a two carbon alkene ==Codes or abbreviations==

C2 may be a code or abbreviation for: • C2 Aquarii, a star • C2 Centauri, a star • C2 (Code Geass), an anime character • C2 explosive, a form of plastic explosive • C2 pylon, a type of high voltage pylon • C2 radio class, a class in FM broadcasting in America • C2 (classification), a para-cycling classification • Group C2, the secondary class of Group C sports car racing • Nimrod NRA/C2, a 1982 Group C racing car • C2, an international standard paper size defined in ISO 216 (458×648 mm) • C2, a level in the Common European Framework of Reference for Languages • C2, the NRS social grade between C1 and D • C2s, substances listed in Schedule II of the Controlled Substances Act in the United States • Command and control, the exercise of authority by a commanding officer over military forces in the accomplishment of a mission • Air Luxor IATA airline code • C2 Pictures, a film company related to Carolco Pictures • Bill C-2, various legislation of the Parliament of Canada • C2, or C2 a note-octave in music, aka Low C ==Computing==

• C2, a computer security class, defined in the Trusted Computer System Evaluation Criteria • C2, a bytecode compiler that is part of the HotSpot virtual machine implementation • C2 (protocol), a 1985 Commodore file transfer protocol • C2 error, a read error of a compact disc • C2.com or WikiWikiWeb, the first user-editable website • C2 (consulting firm), an initialism for, and Cunningham and Cunningham, a technology consulting firm founded by Ward Cunningham • Cryptomeria cipher, a cipher used in digital rights management • Command and control (malware) • Codec 2, speech compression codec. ==Transportation and space==

• C2 class Melbourne tram • Bavarian C II (Ostbahn), an 1862 German steam locomotive • Bavarian C II.1, an 1857 German steam locomotive • Bavarian C II.2, an 1861 German steam locomotive • Chevrolet Corvette (C2), the generation of the Chevrolet Corvette produced between 1962 and 1967 • Citroën C2, a car produced by Citroën in 2004 • Cluster II (spacecraft), an ESA space mission • Ford C2 platform, an automobile platform produced by Ford since 2018 • GNR Class C2, a British 4-4-2 steam locomotive class • LNER Class C2, classified C1 during GNR ownership • Kawasaki C2, a bike • London Buses route C2 • LB&SCR C2 class, an 1893 British 0-6-0 steam locomotive • Circumferential Road 2 or C-2, an arterial road of Manila, Philippines • Saf-T-Liner C2, a school bus built by Thomas Built Buses • Saturn C-2, a 1960 conceptual American launch vehicle • Type C2 ship, a type of all-purpose cargo ship • C2 (yacht), a luxury motor yacht • Central Circular Route (Shuto Expressway) in Tokyo, Japan • Mei-Nikan Expressway, route C2 in Nagoya, Japan ==Military and aviation==

• Command and control, the exercise of authority and direction by a commanding officer • C-2 (poison), developed in the Poison laboratory of the Soviet secret services • C2A1, Squad Automatic Weapon variant of the FN FAL formerly in Canadian Service • ACAZ C.2, a Belgian prototype fighter aircraft of the 1920s • AEG C.II, a German World War II armed reconnaissance aircraft • Aeronca C-2, an American airplane • AGO C.II, a German reconnaissance biplane of World War I • Cierva C.2, a 1921 Spanish experimental autogyro • DFW C.II, a World War I German reconnaissance aircraft • Fokker C-2, the American military version of the Fokker F.VII aircraft • C-2 Greyhound, the Grumman cargo aircraft of the United States Navy • , a British C class submarine of the Royal Navy • Kawasaki C-2, a military transport aircraft • LFG Roland C.II, a 1915 advanced German reconnaissance aircraft • LVG C.II, a 1910s German two-seat reconnaissance biplane • , a C-class submarine of the United States Navy • , a protected cruiser of the United States Navy ==Other==

• C2, UEFA Cup Winners' Cup in football, later merged with UEFA Cup (now UEFA Europa League) • C2 Pictures, a film studio • C-2 visa, a nonimmigrant visa which allows individuals to travel to and from the headquarters of the United Nations • Coca-Cola C2, a soft drink launched by The Coca-Cola Company in 2004 • Conduit 2, a 2011 first-person shooter video game • AEW Continental Classic, a professional wrestling tournament ==See also==