CO

• Carbon monoxide (CO), a colorless, odorless, and tasteless gas • Carbonyl group, composed of a carbon atom double-bonded to an oxygen atom: C=O • Cobalt, a chemical element, symbol Co == Computing and telecommunications ==

• .co (second-level domain), the Internet second-level domain meaning "commercial" • .co, the Internet country code top-level domain (ccTLD) for Colombia • Commitment ordering (CO), a concurrency control technique for databases • Telephone exchange, or central office (CO) == Mathematics ==

• Cofunction, or Co, in trigonometry • Cuboctahedron, a uniform polyhedron ==People==

• Nguyễn Hữu Có (1925–2012), Vietnamese general • Conrado Co (born 1940), Filipino badminton player • Alfredo Co (born 1949), Filipino Sinologist • Atoy Co (born 1951), Filipino actor and basketball coach • Leonard Co (1953–2010), Filipino botanist • Marivic Co-Pilar (born 1971), Filipino politician • Nando Có (born 1973), Bissau-Guinean footballer • Kenedy Có (born 1998), Bissau-Guinean footballer • Samuel S. Co, Filipino politician == Places ==

• CO postcode area, or Colchester postcode area, England • Colombia, ISO 3166-1 country code CO • Colorado, United States postal abbreviation CO • Counties of Ireland, abbreviated Co. == Ranks and titles ==

• C.O., post-nominal initials of members of the congregation of the Oratory of Saint Philip Neri • C/O, cadet officer ranks of the Junior Reserve Officers' Training Corps • Commanding officer (CO), the officer in command of a military unit • Contracting Officer (CO or KO), in the U.S. government • Correctional officer (CO), an officer whose duty it is to safeguard and promote the welfare of inmates • Circle officer (CO), in the Indian government • Conscientious objector == Transportation ==

• Chemins de fer Orientaux (CO), a former Ottoman railway company • Chesapeake and Ohio Railway (C&O or CO), a former American railroad • Cobalt Air (IATA airline designator CO, 2016-2018), a Cypriot airline • Continental Airlines (IATA airline designator CO, 1937-2012), an American airline == Other uses ==

• co-, an English prefix meaning coming together • Cardiac output (CO), the volume of blood being pumped by the heart per time unit • Castres Olympique, a French rugby club • Certificate of occupancy (CO), a legal document • Certificate of origin (often abbreviated to C/O or CoO), in international trade • Company, abbreviated co. • Corsican language, ISO 639-1 language code co • (), a character in the Unicode Letterlike Symbols block, meaning 'care of' • c/o, former name of Gerhardsen Gerner, an art gallery in Berlin == See also ==