CO

CO, Co, co, .co, c/o ℅ may refer to:

Mathematics, science, and technology

Biology and medicine

• Cardiac output, the volume of blood being pumped by the heart per time unit
• Coccygeal nerve of the spinal cord

Chemistry

• Cobalt (chemical symbol Co)
• Carbon monoxide, the molecular formula of the toxic gas (also called Carbonous oxide)
• Carbonyl

Electronics and computing

• .co (second-level domain), Internet second-level domain used to denote commercial organizations in many countries
• Commitment ordering or Commit ordering, a concurrency control (serializability) technique for databases and transactional systems

Other uses in mathematics, science, and technology

• co (function prefix) (complementary), a prefix for complementary functions in mathematics
• Changeover switch, a type of electrical switch with both types of opened/closed contacts
• Central office, in telecommunications and telephony

Places

• CO postcode area for Colchester, England
• Colombia, in various country codes
  • .co, the Internet top-level domain for Colombia
• Colorado (United States postal abbreviation)
• Como, Lombardia, Italy
• Central Otago, part of New Zealand's South Island

Ranks and titles

• C.O., post-nominal initials to identify members of the congregation of the Oratory of Saint Philip Neri
• Certified Orthotist
• Chief Officer
• Commanding officer, military
• Commissioned officer, military
• Communications Officer in Central Communications Command
• Conservation officer
• Contracting Officer
• Corrections Officer (or Correctional Officer)

Transport

• Chemins de fer Orientaux, an Ottoman railway company
• Chesapeake and Ohio Railway
• Continental Airlines (IATA airline designator CO) prior to 2012
• Cobalt Air (IATA airline designator CO) after 2015

Other uses

• co-, an English prefix meaning coming together (co-operate, co-curricular activities, co-brother etc.)
• co, a gender-neutral pronoun
• Care of, often written ℅ or c/o, used to address a letter when the letter must pass through an intermediary
• Company, abbreviated co.
• County, abbreviated Co.
• Nguyễn Hữu Có (1925–2012), Vietnamese general
• Certificate of occupancy, a legal document
• Certificate of origin, in international trade
• Conscientious objector, in warfare
• Corsican language, ISO 639 alpha-1

See also

• C0 (disambiguation), the letter-number combination