| Course Identification Number | Academic & Science |
| Centre for Integrative Neuroscience | Academic & Science |
| Convective Inhibition | Academic & Science |
| Computers in Nursing | Academic & Science |
| Computers, Informatics, Nursing | Academic & Science |
| Carroll Ia | Airport Code |
| Customer Identification Number | Banking |
| Cinergy Corporation | Business |
| Company Identification Number | Business |
| Corporação Industrial do Norte | Business |
| Coal Industry Nominees | Business |
| Competition Is Nada | Business |
| City of London Group | Business |
| Carlton Investments Ltd | Business |
| Community Investment Network | Business |
| Chemical Industry Notes | Chemistry |
| Catholic Information Network | Community |
| Community Information Network | Community |
| Console Input Notice | Computing |
| Computational Intelligence and Neuroscience | Computing |
| Cineon | Computing |
| Code Interface Node | Computing |
| Console Input | Computing |
| Candidate Identification Number | Computing |
| Customer Interaction Network | Computing |
| Cyber Intelligence Network | Computing |
| Ini File Change Control File (os/2) | File Type |
| Chart Information Network | General |
| Control Identity And Novelty | General |
| Caribbean International Network | General |
| Conjunctival Intraepithelial Neoplasia | General |
| Client Indentification Number | General |
| Content Identification Number | General |
| Challan Identification Number | General |
| Corporate Identification Number | General |
| Consumer Information Network | General |
| Clinically Integrated Networks | General |
| Calibration Identification Number | General |
| Cervical Interepithelial Neoplasia | General |
| Cooperative Information Network | General |
| Chameleon information NETWORK | General |
| carry in and | General |
| Child In Need | General |
| Cincinnati, Ohio | Governmental |
| Cadet Information Number | Governmental |
| Cincinnati Amtrak Station | Governmental |
| Color Index Number | Governmental |
| CHINTAKUNTA | Indian Railway Station |
| Client Index Number | Insurance |
| Cuba International Network | International |
| Coordinadora Interinstitucional Nacional | International |
| Cervical Interepithelial Neoplasm | Medical |
| Contrast-Induced Nephropathy | Medical |
| Children In Need | Medical |
| Chromosomal Instability | Medical |
| Carcinoma Intraepithelial Neoplasia | Medical |
| Cervical Intra-epithelial Neoplasia | Medical |
| Chemotherapy Induced Neutropenia | Medical |
| Corporate Identity Number | Messaging |
| Cargo Increment Number | Military and Defence |
| Container Identification Number | Military and Defence |
| Center Information Network | Space Science |
| Cincinnati Reds | Sports |
| Craft Identification Number | Transport & Travel |