| Abbreviation | Definition |
|---|---|
| CNHS | Central Newcastle High School |
| CNHS | Central Noble High School |
| CNHS | Colts Neck High School |
| CNHS | Columbus North High School |
| CNIS | Christ Nagar International School |
| CNPS | Cardiff North Public School |
| CNPS | Carney Nadeau Public School |
| CNSAT | Cabarroguis National School of Arts and Trades |
| CNSAT | Cabucgayan National School of Arts and Trades |
| COAGS | Colorado Outdoor Adventure Guide School |
| COBS | Colorado Outward Bound School |
| CODE | Council of Ontario Directors of Education |
| CODE | Council of Ontario Drama and Dance Educators |
| CODIS | Commission on Diversity in Independent Schools |
| CODS | Coloma Outdoor Discovery School |
| COES | Creekside Oaks Elementary School |
| COHS | Canyon Oaks High School |
| COHS | Cardinal O'Hara High School |
| COHS | Charter Oak High School |
| COHS | Cosumnes Oaks High School |