Co

CO can stand for:

• Carbon monoxide (chemical symbol)
• Central office (telecommunications and telephony)
• Chesapeake and Ohio Railroad (AAR reporting mark CO)
• Colombia (ISO 3166–1 digram and NATO country code)
• Colorado (U.S. postal symbol)
• Commanding officer (military)
• Conscientious objector (military)
• Continental Airlines (IATA airline code)

Co can stand for:

• Co is an UIC classification of railroad locomotive wheel arrangement, known as 0–6–0 in the Whyte notation
• an ethnic group in Southeast Asia
• Cobalt (ferromagnetic metallic chemical element)
• Company (Co.) (general business abbreviation)

co can stand for:

• check out (RCS command)
• a gender-neutral pronoun
• a prefix (form of com-, signifying with, together, in conjunction, joint)

c/o can stand for:

• Care of (postal code used for temporary address change)