Cabinet Office
• British fishing port registration for Caernarvon
• Med. cardiac output
• careers officer
• central office
• Chief Officer
• Clerical Officer
• postcode for Colchester
• international vehicle registration for Colombia
• US postcode for Colorado
• Military combined operations
• Commanding Officer
• command order
• Commissioner of Oaths
• Commonwealth Office (now part of the FCO)
• Finance compte ouvert (French: open account)
• conscientious objector
• airline flight code for Continental Airlines
• criminal offence
• Crown Office
• Electronics current oscillations
• Biochem. cyclo-oxygenase
• British vehicle registration for Exeter