| COS | Comité des Oeuvres Sociales | In French | → Social welfare |
| COSOR | Comité des Œuvres Sociales de la Résistance | In French | → Organizations and associations → Social welfare → History |
| COSPAC | Cost/Schedule Planning And Control | In English | → Prices |
| COST | Co-operation in the field of Scientific and Technical Research | In English | → Research policy → European Union |
| COTAM | Commandement du Transport Aérien Militaire | In French | → Public administration, government → Military engineering → Transport and postal services |
| COTOREP | Commission Technique d'Orientation et de Reclassement Professionnel | In French | → Labour, labour economics → Public administration, government |
| COTPAL | Comité Técnico Permanente sobre Asuntos Laborales = COTPAL | Comitê Técnico Permanente sobre Assuntos Trabalhistas | In Portuguese |
In Spanish | → Labour, labour economics |
| COTPAL | Comitê Técnico Permanente sobre Assuntos Trabalhistas = (look above) |
In Portuguese | → Labour, labour economics |
| COTR | Contracting Officer's Technical Representative | In English | → 3474 |
| COTSEAL | Council of Teachers of Southeast Asian Languages | In English | → Organizations and associations → Education → Language, linguistics, literature |
| CoUCL | Contributions de l'Universite Catholique de Louvain | In French | → Serial publications, periodicals → Roman catholic church → Higher education, universities |
| COV | Centrum Ontmoeting der Volkeren | In Dutch | → Organizations and associations → Development |
| CP | Certificat Préparatoire | In French | → Education |
| CPA | Cessation Progressive d'Activité | In French | → Labour, labour economics |
| CPA | Centre de Perfectionnement aux Affaires | In French | → Economics → Education |
| CPA | Cost Per Action | In English | → Prices → 659 |
| CPA | Classification of Products by Activity | In English | → 3384 |
| CPAF | Cost Plus Award Fee | In English | → Prices |
| CPC | Commission Parlementaire Conjointe = CPC | Comisión Parlamentaria Conjunta | In Spanish = CPC | Comissão Parlamentar Comum | In Portuguese |
In French | → Parliaments, representation |
| CPC | Comisión Parlamentaria Conjunta = (look above) |
In Spanish | → Parliaments, representation |
| CPC | Comissão Parlamentar Comum = (look above) |
In Portuguese | → Parliaments, representation |
| CPCAM | Caisse Primaire Centrale d'Assurance-Maladie | In French | → Insurance → Medicine |
| CPCAMRP | Caisse Primaire Centrale d'Assurance-Maladie de la Région Parisienne | In French | → Insurance → Medicine |
| CPCEA | Caisse de Prévoyance des Cadres d'Exploitations Agricoles | In French | → Insurance → Agricultural sciences |
| CPCI | Commission Permanente de Concertation pour l'Industrie | In French | → Industry, industrial policy |
| CPCSS | College Preparatory Charter School of Springfield | In English | → Education |
| CPE | Certificate of Proficiency in English | In English | → Education → Language, linguistics, literature |
| CPE | Contrat Première Embauche | In French | → Labour, labour economics |
| CPEG | Certificat Préparatoire aux Études de Gestion | In French | → Economics → Education |
| CPER | Contrat de Projets État/Région | In French | → Public administration, government |
| CPER | Contrat de Plan État-Région | In French | → Public administration, government |
| CPER | Contrats de plan État-région | In French | → Internal policy → Public administration, government |
| CPF | Cost Per Flight | In English | → Prices → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| CPFF | Cost Plus Fixed Fee | In English | → Prices |
| CPG | Consumers Packaged Goods | In English | → Economics |
| CPGE | Classes Préparatoires aux Grandes Écoles | In French | → Education |
| CPGE | Classe Préparatoire aux Grandes Écoles | In French | → Education |
| CPI | Cycle Préparatoire Intégré | In French | → Education |
| CPI | Cour Pénale Internationale = ICC | International Criminal Court | In English |
In French | → Law, jurisprudence |
| CPI | Centro de Promoción de Inversiones | In Spanish | → 33972 |
| CPI | Centre de Promotion des Investissements | In French | → 33972 |
| CPIF | Cost Plus Incentive Fee | In English | → Prices |
| CPM | Cost and Performance Measurement | In English | → Prices |
| CPM | Contract Performance Management | In English | → Management → 3474 |
| CPN | Commission Pédagogique Nationale | In French | → Education |
| CPNAMB | Caisse Primaire Nationale d'Assurance-Maladie de la Batellerie | In French | → Insurance → Medicine → Transport and postal services |
| CPNEF/AV | Commission Paritaire Nationale de l'Emploi et de la Formation dans l'Audiovisuel | In French | → Labour, labour economics → Cinema, movies → Telecommunications |
| CPNT | Chasse, Pêche, Nature, Traditions | In French | → Political parties and movements |
| CPP | Cycle Préparatoire Polytechnique | In French | → Education |
| CPP | Code de procédure pénale | In French | → Law, jurisprudence |
| CPP | Commission Psycho-Pédagogique | In French | → Psychology → Education |
| CPPN | Classe Pré-Professionnelle de Niveau | In French | → Labour, labour economics → Education |
| CPPOSS | Caisse de Prévoyance du Personnel des Organismes Sociaux et Similaires | In French | → Insurance |
| CPR | Cost Performance Report | In English | → Prices |
| CPR | Centre for Policy Research | In English | → Politics |
| CPS | Crown Prosecution Service | In English | → Public administration, government |
| CPS | Comunità Promozione e Sviluppo | In Italian | → Organizations and associations → Development |
| CPSM | Caisse de Protection Sociale de Mayotte | In French | → Insurance |
| CPSR | Contractor's Procurement System Review | In English | → 3474 |
| CPU | Collège Polytechnique Universitaire | In French | → Specialized or (poly)technical colleges → Engineering, technology |
| CPU | Conférence des Présidents d'Université | In French | → Higher education, universities |
| CPV | Communist Party of Vietnam | In English | → Political parties and movements |
| CPY | Communist Party of Yugoslavia | In English | → Political parties and movements |
| CQFH | Comité sur les Questions Financières de l'Hémisphère = CAFH | Comité de Asuntos Financieros Hemisféricos | In Spanish = CAFH | Comitê de Assuntos Financeiros no Hemisfério | In Portuguese = CHFI | Committee on Hemispheric Financial Issues | In English |
In French | → Finance → International economic cooperation |
| CQNUMC | Convenção-Quadro das Nações Unidas sobre Mudança de Clima (http://unfccc.int) = UNFCCC | United Nations Framework Convention on Climate Change | In English = CMNUCC | Convenio Marco de las Naciones Unidas sobre Cambio Climático | In Spanish = CCNUCC | Convention-Cadre des Nations Unies sur les Changements Climatiques | In French = UNFCCC | 聯合國氣候變化綱要公約 | In Chinese = КИК | Рамочная конвенция ООН об изменении климата | In Russian = UNFCCC | 気候変動枠組条約 | In Japanese = UNFCCC | 기후 변화에 관한 국제 연합 기본 협약 | In Korean |
In Portuguese | → United Nations → Meteorology, climatology |
| CR | Contractor's Response | In English | → 3474 |
| CRA | Centre de Rétention Administrative | In French | → Law, jurisprudence |
| CRA | Cédants et Repreneurs d'Affaires | In French | → Economics |
| CRAF | Centre Royaliste d'Action Française | In French | → Political parties and movements |
| CRAM | Caisse Régionale d’Assurance Maladie | In French | → Social welfare → Medicine |
| CRAMCO | Caisse Régionale d'Assurance-Maladie du Centre Ouest | In French | → Insurance → Medicine |
| CRAMIF | Caisse Régionale d'Assurance-Maladie de l'Île-de-France | In French | → Insurance → Medicine |
| CRAN | Conseil Représentatif des Associations Noires | In French | → Organizations and associations |
| CRAPE | Centre de Recherche sur l'Action Politique en Europe | In French | → Research institutes → Sociology → Politics |
| CRAS | Cost Reduction Alternative Study | In English | → Prices |
| CRC | Cost Reduction Curve | In English | → Prices |
| CRC | Curso de Representação Comercial | In Portuguese | → Education → Trade |
| CRCA | Caisse Régionale de Crédit Agricole | In French | → Finance |
| CRCCH | Conseil Régional Consultatif des Citoyen(ne)s Handicapé(e)s | In French | → Social welfare |
| CRCE | Centrul Român de Comerţ Exterior | In Romanian | → Trade |
| CRCI | Commission Régionale de Conciliation et d'Indemnisation | In French | → Public administration, government |
| CRCI | Chambre Régionale de Commerce et d'Industrie | In French | → Organizations and associations → Industry, industrial policy |
| CRD | Cost Reporting Document | In English | → Prices |
| CRDI | Centre de Recherches pour le Développement International = IDRC | International Development Research Centre | In English |
In French | → Development |
| CRDI | Centre de Ressources Didactiques Informatisées | In French | → Education |
| CRDP | Centre Régional de Documentation Pédagogique | In French | → Libraries → Education |
| CRE | Conférence des Recteurs Européens | In French | → Organizations and associations → Higher education, universities |
| CREA | Canadian Real Estate Association | In English | → Associations → Accommodation |
| CREAI | Centre Régional de l'Enfance et de l'Adolescence Inadaptée | In French | → Social welfare → Education |
| CREDES | Centre de Recherche, d'Étude et de Documentation en Économie de la Santé | In French | → Economics → Pharmacology, toxicology |
| CREM | Centre de Recherche en Économie et Management | In French | → Research institutes → Economics → Management |
| CREP | Centre de Recherche Économique sur l'Épargne | In French | → Finance |
| CREPAUC | Centre Régional d'Éducation Permanente en Architecture, Urbanisme et Construction | In French | → Education → Building → Regional planning → Architecture |
| CREPS | Centre Régional d'Éducation Physique et Sportive | In French | → Education → Sport, physical exercises |
| CRESCA | Chambre Régionale de l'Économie Sociale de Champagne-Ardenne | In French | → Economics |
| CREST | Centre de Recherche en Économie et STatistique | In French | → Statistics → Economics |
| CRIDEL | Centre de Rencontres et d'Initiatives pour le Développement Local | In French | |
| CRIF | Conseil Régional d'Ile-de-France | In French | → Public administration, government |
| CRIFP | Centre de Recherche en Ingénierie Financière et Finances Publiques | In French | → Finance |
| CRII | Committee for Regional Integration of Inputs = CIRI | Comité de Integración Regional de Insumos | In Spanish = CIRI | Comité sur l'Intégration Régionale des Intrants | In French = CIRI | Comitê de Integração Regional de Insumos | In Portuguese |
In English | → International economic cooperation |
| CRIN | Child Rights Information Network | In English | → Fundamental rights |
| CRIPI | Commission Régionale pour l'Insertion des Populations Immigrées | In French | |
| CRISMS | Commission Régionale des Institutions Sociales et Médico-Sociales | In French | → Social welfare → Medicine |
| CRM | Customer Relationship Management = GRC | Gestion de la Relation Client | In French |
In English | → Economics |
| CRN | Course Reference Number | In English | → Education |
| CRN | Contract Revision Number | In English | → 3474 |
| CRN | Caisse de Retraite des Notaires | In French | → Labour, labour economics → Law, jurisprudence → Insurance |
| CROIR | Centre de Ressources et d'Observation de l'Innovation Religieuse | In French | → Religion, theology |
| CROUS | Centre Régional des Œuvres Universitaires et Scolaires | In French | → Social welfare → Education |
| CRP | Centre de Rééducation Professionnelle | In French | → Labour, labour economics → Education |
| CRPA | Commission Royale sur les Peuples Autochtones = RCAP | Royal Commission on Aboriginal Peoples | In English |
In French | → Politics |
| CRPCC | Centre de Recherches en Psychologie, Cognition et Communication | In French | → Research institutes → Psychology → Sociology |
| CRPE | Concours de Recrutement de Professeur des Écoles | In French | → Education |
| CRPN | Caisse de Retraite du Personnel Navigant | In French | → Labour, labour economics → Insurance → Transport and postal services |
| CRPNPAC | Caisse de Retraite du Personnel Navigant de l'Aéronautique Civile | In French | → Labour, labour economics → Insurance → Transport and postal services |
| CRR | Commission des Recours des Réfugiés | In French | → Demography, statistics, sociology → Law, jurisprudence |
| CRS | Congressional Research Service | In English | → Parliaments, representation |
| CRS | Compagnie Républicaine de Sécurité | In French | → Police |
| CRSN | Cadre de Référence Stratégique National | In French | → Central administration |
| CRT | Comité Régional du Tourisme | In French | → Tourism |
| CRTP | Cultural Restoration Tourism Project | In English | → Civilization, culture, progress → Tourism |
| CRU | Comité Réseau des Universités (www.cru.fr) | In French | → Higher education, universities |
| CSA | Contrôle Sanction Automatisé | In French | → Public administration, government → Transport and postal services |
| CSA | California Sociological Association | In English | → Associations → Sociology |
| CSA | Contract Specification Amendment | In English | → 3474 |
| CSA | Contractor Support Area | In English | → 3474 |
| CSAA | Canadian Sociology and Anthropology Association | In English | → Associations → Sociology |
| CSAAR | Centre for the Study of Australia-Asia Relations | In English | → International relations → Area studies |
| CSAUS | Chinese School Association in the United States | In English | → Associations → Education → Language, linguistics, literature |
| CSB | Class Schedule Book | In English | → Education |
| CSC | Confédération des Syndicats Chrétiens = ACV | Algemeen Christelijk Vakverbond | In Dutch |
In French | → Organizations and associations → Labour, labour economics → Christianity |
| CSCB | Contractor's Summary Cost Breakdown | In English | → Prices |
| CSCE | Conférence sur la Sécurité et la Coopération en Europe = CSCE | Conference on Security and Co-operation in Europe | In English |
In French | → International relations → European Union |
| CSCE | Conference on Security and Co-operation in Europe = (look above) |
In English | → International relations → European Union |
| CSCS | Centre for the Study of Culture & Society | In English | → Research institutes → Civilization, culture, progress |
| CSD | Centrale des Syndicats Démocratiques | In French | → Organizations and associations → Labour, labour economics |
| CSD | Contract Start Date | In English | → 3474 |
| CSDR | Confederaţia Sindicatelor Democratice din România | In Romanian | → Organizations and associations → Labour, labour economics |
| CSE | Comité Spécial sur les Échanges = SCT | Special Committee on Trade | In English = CEC | Comissão Especial de Comércio | In Portuguese |
In French | → Trade |
| CSE | College of Saint Elizabeth | In English | → Education |
| CSEd | Computer Science Education | In English | → Serial publications, periodicals → Computer science → Education |
| CSEN | Center for the Study of Eurasian Nomads | In English | |
| CSF | Cost Sensitivity Factor | In English | → Prices |
| CSG | Contribution Sociale Généralisée | In French | → Insurance |
| CSGSS | Chinese Studies Graduate Summer School | In English | → Education → Language, linguistics, literature |
| CSH | Comissão de Segurança Hemisférica = CSH | Comisión de Seguridad Hemisférica | In Spanish = CHS | Committee on Hemispheric Security | In English |
In Portuguese | → International relations |
| CSH | Comisión de Seguridad Hemisférica = CHS (look above) |
In Spanish | → International relations |
| CSHSP | Collectif de Soutien des Homos Sans Papiers | In French | → Organizations and associations → 3472 |
| CSI | Confédération Syndicale Internationale | In French | → International relations → Labour, labour economics |
| CSI-CSIF | Confederación de Sindicatos Independientes y Sindical de Funcionarios | In Spanish | → Organizations and associations → Labour, labour economics |
| CSID | Center for the Study of Islam and Democracy | In English | → Islam → Democracy |
| CSIRO | Commonwealth Scientific and Industrial Research Organization (www.csiro.au) | In English | → Organizations and associations → International relations → Research policy → Engineering, technology |
| CSIS | Centre for Strategic and International Studies | In English | → International relations |
| CSME | CARICOM Single Market and Economy | In English | → International economic cooperation |
| CSN | Coopérant du Service National | In French | → Labour, labour economics → Public administration, government |
| CSOEC | Conseil Supérieur de l'Ordre des Experts-Comptables | In French | → Organizations and associations → Commercial law → Accounting |
| CSPI | Conseil Supérieur de la Propriété Intellectuelle | In French | → Industrial property |
| CSPLA | Conseil Supérieur de la Propriété Littéraire et Artistique | In French | → Artistic property |
| CSPT | Conference for the Study of Political Thought | In English | → Organizations and associations → Politics |
| CSQ | Contrôle Statistique de la Qualité | In French | → Data → Statistics |
| CSR | Contract Status Report | In English | → 3474 |
| ČSSD | Česká Strana Sociálně Demokratická | In Czech | → Political parties and movements |
| CSSH | Comparative Studies in Sociology and History | In English | → Sociology → History |
| CSSS | Centre for Study of Society and Secularism | In English | → Sociology |
| CSSSCAL | Centre for Studies in Social Sciences | In English | |
| CSSTM | Centre de Sécurité Sociale des Travailleurs Migrants | In French | → Migrations → Insurance |
| CSTO | Collective Security Treaty Organization | In English | → Organizations and associations → International relations |
| CSU | Cultures et Sociétés Urbaines | In French | → Sociology |
| CSUE | Centro de Satélites de la Unión Europea (www.eusc.europa.eu) = EUSC | European Union Satellite Centre | In English = CSUE | Centro Satellitare dell'Unione Europea | In Italian |
In Spanish | → European Union → Spaceflight engineering, astronautics |
| CSUE | Centro Satellitare dell'Unione Europea (www.eusc.europa.eu) = EUSC (look above) |
In Italian | → European Union → Spaceflight engineering, astronautics |
| CSV | Chrëschtlech Sozial Vollekspartei | In Letzeburgesh | → Political parties and movements |
| CTBTO | Comprehensive Nuclear-Test-Ban Treaty Organization | In English | → Organizations and associations → International relations → Nuclear technology |
| CTC | Congrès du Travail du Canada = CLC | Canadian Labour Congress | In English |
In French | → Organizations and associations → Labour, labour economics |
| CTCFL | Centre for Teaching Chinese as a Foreign Language | In English | → Education → Language, linguistics, literature |
| CTCI | Contract Technical Compliance Inspection | In English | → Quality management → 3474 |
| CTDC | Centre Technique Départemental de la Consommation | In French | → Economics |
| CTEU | Centre de Télé-Enseignement Universitaire | In French | → Higher education, universities → Telecommunications |
| CTFVP | Commission pour la Transparence Financière de la Vie Politique | In French | → Political parties and movements → Economics |
| CTH | Conseiller pour les Travailleurs Handicapés | In French | → Labour, labour economics → Medicine |
| CTI | Commission des Titres d'Ingénieur | In French | → Specialized or (poly)technical colleges → Engineering, technology |
| CTI | Centre de Techniques Internationales (www.cti-learning.com) | In French | → Education → Management |
| CTI | Commission des Titres d’Ingénieur (www.cti-commission.fr) | In French | → Organizations and associations → Specialized or (poly)technical colleges |
| CTIBO | Capacity Building of Chinese Technological Intermediary Business Organisations | In English | → Trade → Engineering, technology |
| CTM | Contract Technical Manager | In English | → 3474 |
| CTNERHI | Centre Technique National d'Études et de Recherches sur les Handicaps et les Inadaptations | In French | → Medicine |
| CTP | Contrat de Transition Professionnelle | In French | → Labour, labour economics → Education |
| CTPBEC | Chinese Taipei Pacific Basin Economic Committee | In English | → Economics |
| CTPECC | Chinese Taipei Pacific Economic Cooperation Committee | In English | → Economics |
| CTR | Contract Technical Representative | In English | → 3474 |
| CTSA | Central Tibetan Schools Administration | In English | → Public administration, government → Education |
| CU | Certificat d'Université | In French | → Education |
| CUAMM | Collegio Universitario Aspiranti e Medici Missionari | In Italian | → Specialized or (poly)technical colleges → Medicine |
| CUCS | Contrat Urbain de Cohésion Sociale | In French | → Social welfare → Regional planning |
| CUDL | Communauté Urbaine de Lille | In French | → Public administration, government → Regional planning |
| CUE | Consejo de la Unión Europea | In Spanish | → International relations |
| CUEJ | Centre Universitaire d'Enseignement du Journalisme | In French | → Higher education, universities → Newspapers, journalism |
| CUH | Code de l'Urbanisme et de l'Habitation | In French | → Public administration, government → Building → Regional planning |
| CUHK | Chinese University of Hong Kong | In English | → Higher education, universities |
| CUIO | Cellule Universitaire d'Information et d'Orientation | In French | → Labour, labour economics → Higher education, universities |
| CUP | Centre Universitaire Provincial | In French | → Higher education, universities |