• Co, the chemical symbol for the element cobalt
  Cobalt
  Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....
  
  
• Co., an abbreviation for Company
  Company
  A company is a form of business organization. It is an association or collection of individual real persons and/or other companies, who each provide some form of capital. This group has a common purpose or focus and an aim of gaining profits. This collection, group or association of persons can be...
  
  
• Carbon monoxide
  Carbon monoxide
  Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
  
  , the molecular formula of the toxic gas (also called carbonic oxide)
• C.O., post-nominal initials to identify members of the congregation of the Oratory of Saint Philip Neri
  Oratory of Saint Philip Neri
  The Oratory of Saint Philip Neri is a congregation of Catholic priests and lay-brothers who live together in a community bound together by no formal vows but only with the bond of charity. They are commonly referred to as Oratorians...
  
  
• .co
  .co
  .co is the country code top-level domain assigned to the Republic of Colombia. It is administered by .CO Internet S.A.S., a strategic venture formed between Arcelandia S.A. and Neustar, Inc...
  
  , the Internet top-level domain for Colombia
• .co (second level)
  .co (second level)
  .co is a second-level domain analogous to .com in a number of countries, in which registrants may register second-level domains of the form .co.xx, where xx is the ccTLD .co (abbreviation of commercial) is a second-level domain analogous to .com (in a strictly second-level sense) in a number of...
  
  , Internet second-level domain used to denote commercial organizations in many countries
• CO postcode area
  CO postcode area
  The CO postcode area, also known as the Colchester postcode area, is a group of postcode districts around Bures, Clacton-on-Sea, Colchester, Frinton-on-Sea, Halstead, Harwich, Manningtree, Sudbury and Walton-on-the-Naze in England....
  
   for Colchester, England
• Cardiac output
  Cardiac output
  Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
  
  , the volume of blood being pumped by the heart per time unit
• Central office, in telecommunications and telephony
• Certificate of Occupancy
  Certificate of occupancy
  A Certificate of Occupancy is a document issued by a local government agency or building department certifying a building's compliance with applicable building codes and other laws, and indicating it to be in a condition suitable for occupancy....
  
  , a legal document
• Certificate of origin
  Certificate of origin
  A Certificate of Origin is a document used in international trade. It traditionally states from what country the shipped goods originate, but "originate" in a CO does not mean the country the goods are shipped from, but the country where the goodtion problem in cases where less than 100% of the...
  
  , used in international trade
• Champions Online
  Champions Online
  Champions Online is a free-to-play superhero-themed massively multiplayer online role-playing game by former City of Heroes/Villains developer Cryptic Studios based on the Champions license. The game's rules and setting are loosely based on the HERO System ruleset...
  
  , an MMO Action/RPG game developed by Cryptic Studios
• Check out, a Revision Control System
  Revision Control System
  The Revision Control System is a software implementation of revision control that automates the storing, retrieval, logging, identification, and merging of revisions. RCS is useful for text that is revised frequently, for example programs, documentation, procedural graphics, papers, and form...
  
   command
• Chesapeake and Ohio Railway
  Chesapeake and Ohio Railway
  The Chesapeake and Ohio Railway was a Class I railroad formed in 1869 in Virginia from several smaller Virginia railroads begun in the 19th century. Led by industrialist Collis P...
  
  
• Chinese Orchestra
  Chinese orchestra
  The term Chinese Orchestra can refer to either:* The ancient Chinese Orchestra, or* The modern Chinese Orchestra-The ancient Chinese Orchestra:...
  
  
• Coccygeal nerve
  Coccygeal nerve
  -Structure:The coccygeal nerve is the 31st spinal nerve. It arises from the sacral plexus, and its ventral ramus helps form the coccygeal plexus. It does not divide into a medial and lateral branch...
  
   of the spinal cord
• Colombia
  Colombia
  Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
  
  , in various country codes
• Colonial Office
  Colonial Office
  Colonial Office is the government agency which serves to oversee and supervise their colony* Colonial Office - The British Government department* Office of Insular Affairs - the American government agency* Reichskolonialamt - the German Colonial Office...
  
  , a former UK government department
• Colorado
  Colorado
  Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
  
   (United States postal abbreviation)
• Command (disambiguation)
• Commitment ordering
  Commitment ordering
  In concurrency control of databases, transaction processing , and related applications, Commitment ordering is a class of interoperable Serializability techniques, both centralized and distributed. It allows optimistic implementations...
  
   or Commit ordering, a concurrency control (serializability) technique for databases and transactional systems
• Como
  Como
  Como is a city and comune in Lombardy, Italy.It is the administrative capital of the Province of Como....
  
  , Lombardia, Italy
• Company
  Company
  A company is a form of business organization. It is an association or collection of individual real persons and/or other companies, who each provide some form of capital. This group has a common purpose or focus and an aim of gaining profits. This collection, group or association of persons can be...
  
   (co.), a general business abbreviation
• Compliance officer, a title used by the Food and Drug Administration for agents charged with enforcing its policies
• Computer organization
• Conjure One
  Conjure One
  Conjure One is a Canadian electronic music project, headed by Rhys Fulber, better known as a member of Front Line Assembly and Delerium, as well as other musical groups alongside Bill Leeb.-History:...
  
  , Canadian music artist
• Conquer Online, a MMORPG PC game
• Conscientious objector
  Conscientious objector
  A conscientious objector is an "individual who has claimed the right to refuse to perform military service" on the grounds of freedom of thought, conscience, and/or religion....
  
  , military
• Continental Airlines
  Continental Airlines
  Continental Airlines was a major American airline now merged with United Airlines. On May 3, 2010, Continental Airlines, Inc. and UAL, Inc. announced a merger via a stock swap, and on October 1, 2010, the merger closed and UAL changed its name to United Continental Holdings, Inc...
  
  , IATA airline designator
• Corsican language
  Corsican language
  Corsican is a Italo-Dalmatian Romance language spoken and written on the islands of Corsica and northern Sardinia . Corsican is the traditional native language of the Corsican people, and was long the vernacular language alongside the Italian, official language in Corsica until 1859, which was...
  
  , according to ISO 639 alpha-1
• Cuboctahedron
  Cuboctahedron
  In geometry, a cuboctahedron is a polyhedron with eight triangular faces and six square faces. A cuboctahedron has 12 identical vertices, with two triangles and two squares meeting at each, and 24 identical edges, each separating a triangle from a square. As such it is a quasiregular polyhedron,...
  
  

People and official titles

• Certified Orthotist
• Chief Officer
  Chief officer
  A chief officer can refer to any of various leaders:In the military, it can refer to certain non-commissioned members:*Chief Petty Officer*Chief Warrant OfficerMarine occupation:*Chief Mate...
  
  
• Commanding officer
  Commanding officer
  The commanding officer is the officer in command of a military unit. Typically, the commanding officer has ultimate authority over the unit, and is usually given wide latitude to run the unit as he sees fit, within the bounds of military law...
  
  , military
• Commissioned officer, military
• Communications Officer in Central Communications Command
  Central Communications Command
  The Central Communications Command is the largest Operational Command Unit OCU of London's Metropolitan Police Service. It sits within Territorial Policing, the business group within the Met that is responsible for Borough Policing and public contact...
  
  
• Conservation officer
  Conservation officer
  A conservation officer is an employee who has the role of protecting conservation values.-United States:*Michigan Conservation Officers*Louisiana Department of Wildlife & Fisheries - Enforcement Division*Maryland Department of Natural Resources Police...
  
  
• Contracting Officer
  Contracting Officer
  A Contracting Officer is a person who can bind the United States government to a contract that is greater than the Micro-Purchase threshold. This is limited to the scope of authority delegated to the Contracting Officer by the head of the agency.In the Department of Defense the acronym KO is...
  
  
• Corrections Officer (or Correctional Officer)

Other

• "care of", used to address a letter when the letter must pass through an intermediary
• "complaining of", the Chief complaint
  Chief complaint
  The Chief Complaint formally known as CC in the medical field, or termed Presenting Complaint in the UK, is a concise statement describing the symptom, problem, condition, diagnosis, physician recommended return, or other factor that is the reason for a medicalencounter...
  
   in the medical record of a presenting patient
• "co", a prefix
  Prefix
  A prefix is an affix which is placed before the root of a word. Particularly in the study of languages,a prefix is also called a preformative, because it alters the form of the words to which it is affixed.Examples of prefixes:...
  
   meaning coming together (co-operate, co-curricular activities, co-brother etc.)
• "c/o", an acronym used in MMORPG
  MMORPG
  Massively multiplayer online role-playing game is a genre of role-playing video games in which a very large number of players interact with one another within a virtual game world....
  
  s, stands for: Current Offer
• "c/o", an acronym used in a medical history
  Medical history
  The medical history or anamnesis of a patient is information gained by a physician by asking specific questions, either of the patient or of other people who know the person and can give suitable information , with the aim of obtaining information useful in formulating a diagnosis and providing...
  
  , stands for: "complaining of"

See also

• C0 (disambiguation) - the letter-number combination