CI or Ci may refer to:
Business terminology Commercial invoice Competitive intelligence Confidential information Continual improvement Corporate identity Customer intelligence, a discipline in marketing
Businesses and organisations Academia and education California State University, Channel Islands Channel Islands High School Collegium Invisibile Confucius Institute
Religion Josephites of Belgium, a Catholic congregation Christian Identity Christian Institute, a British charity which promotes Christian values
Other businesses and organizations CI Financial, Canadian investment management company Charity Intelligence Canada China Airlines (IATA code) Cigna health services (NYSE symbol) Consumers International Cycling Ireland CI Records, a music record label Cambria and Indiana Railroad CANZUK International, organisation which promotes cooperation between Canada, Australia, New Zealand and the UK Conservation International, an international environmental non-governmental organization Communications International, a former global union federation Communist International Children International, a non-profit child sponsorship organization Cryonics Institute, American nonprofit foundation
Law and military Counterintelligence Confidential informant Compliance Inspection, a US Air Force inspection Chief inspector, a police rank Circle inspector, a junior police rank Certificate of identity Civilian Internee, a special status of a prisoner during wartime Civilian Instructor, an adult volunteer in the British Air Training Corps and Canada Air Cadets
Places Ci County, in Hebei, China Cayman Islands Chile (FIPS country code, obsolete NATO country code) Coney Island Cocos (Keeling) Islands, an external territory of Australia Cook Islands, an island-country in the South Pacific Ocean Côte d'Ivoire (ISO country code) Channel Islands Channel Islands of California Carbonia-Iglesias, a province in southern Italy Central India, region of India, abbreviated CI Central India Circuit or C. I. Circuit, a Hindi film distribution circuit comprising parts of Madhya Pradesh (Indian state within central India) Central Islip, New York, a hamlet on Long Island, New York in the US
Science, technology and mathematics Biology and medicine cI protein, a repressor protein of Enterobacteria phage λ Cytoplasmic incompatibility, a reproductive system Cardiac index Ci protein, Cubitus interruptus -protein Coital incontinence Convergence insufficiency Corpulence index Cumulative incidence, used as a measure of disease frequency in epidemiology Cochlear implant Chemical injury syndrome, an increased sensitivity to common chemicals also called multiple chemical sensitivity Chronic illness, a condition that is long-lasting or recurrent Contraindication
Computing .ci, the Internet country code top-level domain (ccTLD) for Côte d'Ivoire Common Interface, for a Conditional Access Module CI+, Common Interface Plus Computational intelligence Configuration item, the fundamental structural unit of a configuration management system Core Image, non-destructive image processing technology Continuous integration, a software-engineering practice of merging developer code into a main code base frequently CodeIgniter, a PHP framework
Earth science Cirrus cloud Convective instability
Mathematics Conditional independence, a type of relation of random variables in probability theory Confidence interval, an interval estimate of a population parameter used in statistics 101 (number) (in Roman numerals) Compound interest Cosine integral (standard mathematical symbols "Ci" and "ci")
Physics Conical intersection, the location of a discrete degeneracy between two electronic states Curie (unit) (Symbol: Ci), a measurement of radioactivity named after Marie Curie Copenhagen interpretation, an interpretation of quantum mechanics Cubic inch, a unit of volume
Other uses in science and technology CI group, a type of carbonaceous chondrite meteorite Carrier interferometry, a radio and optical communication coding technology Chemical ionization, a technique used in mass spectrometry Configuration interaction, a post-Hartree–Fock method used in computational chemistry Contextual inquiry, a user-centered design research method Collective intelligence, a subfield of sociology Colour Index International, a reference database of CI numbers for dyes and pigments Bavarian C I, a steam locomotive with the Royal Bavarian State Railways Compression ignition engine, another name for a diesel engine Cost Index (CI), the ratio of time cost to fuel cost, used to calculate the cruising speed of an airliner
Television Canadian Idol, a Canadian television series Law & Order: Criminal Intent, an American television series Crime & Investigation Network Crime & Investigation Network (Australia), Australian cable and satellite network focusing on Crime Crime & Investigation Network (Europe), a pan-European television channel Crime & Investigation Network (South East Asia)
Other uses Ci (poetry), a form of Chinese lyric poetry Qi, a central concept in several eastern philosophies Categorical imperative, in philosophy Colour Index International, a reference database Comprehensible input Contact improvisation, a dance technique CI, postnominal for Companion of the Order of the Crown of India Ci, a form of the surname Qi, of the Tungusic peoples
See also C1 (disambiguation) CL (disambiguation)