| Abbreviation | Definition |
|---|---|
| CNOC | Curragh Naas Orienteering Club |
| CNRC | Cumberland News Rifle Club |
| CNSB | Club Nautico San Bernardino |
| CNSV | C N S V Club Nautique des Salles sur Verdon |
| CNSV | Club Nautique des Salles sur Verdon |
| CNTC | Club Nautique Tournesol Chasseneuil |
| CNTM | Club Nautique Tyberport Manage |
| CNTO | Carpe Noctem Tactical Operations |
| COAC | Cathedral Oaks Athletic Club |
| COBC | Central Ohio Bicycle Club |
| COC | Cascade Orienteering Club |
| COC | Colby Outing Club |
| COCB | Club Olympique Creusot Bourgogne |
| COCC | champagne and oysters cycling club |
| COCC | Commodore Owners Car Club |
| COCF | Club Olympique Cycliste Fougerais |
| CODC | Club Omnisport de Cruseilles |
| CODM | Club Omnisport De Meknes |
| COFF | Club Obsol??te Ford France?? |
| COFF | Club Obsolète Ford France |