| Clinical Infectious Disease Society | Academic & Science |
| Clinical Infectious Diseases Society | Academic & Science |
| Central Iowa Daylily Society | Academic & Science |
| Central Iowa Dalily Society | Academic & Science |
| Career Information Delivery System | Business |
| Career Information Delivery Systems | Business |
| Collaborative International Development Studies | Community |
| Cultural Industries Development Strategy | Community |
| Cultural Industries Development Service | Community |
| Creative Industries Development Service | Community |
| Community Information Data Set | Community |
| Center for Integrative and Development Studies | Community |
| Creative Industries Development Scheme | Community |
| Centre for International Development Services | Community |
| Component Information Dictionary Standard | Computing |
| Cisco Ids | Computing |
| Computer Information Delivery Service | Computing |
| C Integrated Data System | General |
| Collaborative Intrusion Detection System | General |
| Census Interaction Data Service | General |
| Concrete Island Drilling System | General |
| Chief Of Integrated Defence Staff | General |
| Calling Identity Delivery And Suppression | General |
| Chronological In Depth Structured | General |
| Chronological In Depth Survey | General |
| Centro de Investigación en Demografía y Salud | General |
| Comprehensive Interdisciplinary Developmental Services | General |
| Centre d'intervention en délinquance sexuelle | General |
| Center for Inland Desalination Systems | General |
| Cabin Intercommunication Data System | General |
| Centre for integrity in the defence sector | General |
| Command Information Display System | General |
| Citation Impact Discerning Self | General |
| Client Intrusion Detection System | General |
| Cellular Intrusion Detection System | General |
| Combat Identification for the Dismounted Soldier | Governmental |
| Combat Information Demonstration System | Governmental |
| Collateral Information Display Station | Governmental |
| Critical Information Dispatch System | Governmental |
| Center of International Dispute Settlement | International |
| Canadian Implantable Defibrillator Study | Medical |
| Coorg Institute of Dental Sciences | Medical |
| Clinical Infectious Diseases Specialist | Medical |
| Canadian Infectious Disease Society | Regional |
