| Council for the Study of Community Colleges | Academic & Science |
| Capital South Campus Center | Academic & Science |
| Columbia-Southern Chemical Corporation | Academic & Science |
| Cleveland State Community College, Cleveland, Tennessee | Academic & Science |
| Société Canadienne des Clinico-Chimistes | Academic & Science |
| Cisco Service Contract Center | Business |
| Customer Service Customer Care | Business |
| CenterSpan | Business |
| Slovenian Central Securities Clearing Corporation | Business |
| Columbus State Community College | Community |
| Cleveland State Community College | Community |
| Como Student Community Cooperative | Community |
| Centre for the Study of Communication and Culture | Community |
| Circuits Systems Communications and Computers | Computing |
| Computer Standards Coordinating Committee | Computing |
| Center for Strategic Counterterrorism Communications | General |
| Cutaneous Squamous Cell Carcinoma | General |
| California Sports Car Club | General |
| Canada Sports Car Club | General |
| Classic Sports Car Club | General |
| California Stingrays Car Club | General |
| Colorado Springs Corvette Club | General |
| Chicagoland Sports Car Club | General |
| Council of Sports Car Clubs | General |
| Clemson Sports Car Club | General |
| Cherokee Strip Corvette Club | General |
| Classic Saloon Car Club | General |
| Chrysler Sebring Convertible Club | General |
| Classic and Specialist Car Club | General |
| Communications Sector Coordinating Council | Governmental |
| Cloud Standards Customer Council | Governmental |
| Coastal Sea Control Commander | Governmental |
| Cloud Security Command Center | Internet |
| Canadian Society of Clinical Chemists | Regional |
| Cascade Sports Car Club | Sports |
