| Cold Air Intake | Academic & Science |
| Calcium Aluminum-rich Inclusion | Academic & Science |
| Cold Air Induction | Academic & Science |
| Chartered Accountants Ireland | Accounts and Finance |
| Cairo | Airport Code |
| Contractor Acceptance Inspection | Business |
| Customer Appreciation, Incorporated | Business |
| Confederation of Aerial Industries | Business |
| Cicatelli Associates Inc | Business |
| Cartographic Associates Inc | Business |
| Castle Alt Inv | Business |
| Canadian Income Management Incorporated (de-listed) | Business |
| Certified Auctioneers Institute | Certifications |
| Certified Auctioneer Institute | Certifications |
| Child Adapted Instruction | Community |
| Community Associations Institute | Community |
| Christian Associates International | Community |
| Christian Assemblies International | Community |
| Common Air Interface | Computer and Networking |
| Creative Artificial Intelligence | Computing |
| Computer Assisted Intervention | Computing |
| Computer And Information | Computing |
| Computer Assisted Instruction | Computing |
| Call Assembly Index | Computing |
| Computer Applications Incorporated | Computing |
| Computer Assisted Interviewing | Computing |
| Computer Associates International | Computing |
| Channel Assignment Indicator | Computing |
| Catia Integration | Computing |
| Computer Aided Innovation | Computing |
| Cooperative Applications Initiative | Computing |
| Computer Augmented Instruction | Computing |
| Computer Aided Inspection | Computing |
| Computer Aided Interpreting | Computing |
| Computer Aid Inc | Computing |
| Computer Aided Information | Computing |
| Computer Aided Instructional | Computing |
| Computer Assisted Indexing | Computing |
| Computer Adjusted Instruction | Computing |
| Club Atletico Independiente | Cryptocurrency |
| Computer-aided Indexing | Database Management |
| Construction Administration Inc | General |
| Complejo Agro-Industrial | General |
| Continuous Airworthiness Items | General |
| Controlled Auto Ignition | General |
| Canadian Automotive Instruments | General |
| Club Ayla Indonesia | General |
| Corona Absolute Indonesia | General |
| Canadian Automotive Institute | General |
| Center for Automotive Industry | General |
| Caerbont Automotive Instruments | General |
| Centre for Advanced Imaging | General |
| Content Area Interaction | General |
| Center for Applied Informatics | General |
| Create An Identity | General |
| Combustion Area Inspection | General |
| Compagnia Aeronautica Italiana | General |
| Carl August Immich | General |
| Calcium Aluminum Inclusion | General |
| Centro Alpino Italiano | General |
| Center for Advancing Innovation | General |
| Comando de Accion Imediata | General |
| Calling Assistance Immediately | General |
| Codon Adaptation Index | General |
| Central Asia Institute | Governmental |
| Central Afghanistan Institute | Governmental |
| Community Association Institute | Governmental |
| Caring Attitude Imposter | Governmental |
| CHANPATIA | Indian Railway Station |
| Computer-Aided Instruction | Information Technology |
| Canadian Airlines International | International |
| Century Arms International | International |
| Comit? AntiImperialistas | International |
| Club Alpino Italiano | International |
| Comités AntiImperialistas | International |
| Cubic Applications, Inc. | Military and Defence |
| Combined Arms Initiatives | Military and Defence |
| Central American Indian (Other) | Regional |