| Abbreviation | Definition |
|---|---|
| CHSB | Chichester High School for Boys |
| CHSC | Colorado High School Charter |
| CHSC | Creating Healthy Schools and Communities |
| CHSE | Campaign for High School Equity |
| CHSE | Cranston High School East |
| CHSG | Chichester High School for Girls |
| CHSI | Celebrating High School Innovators |
| CHSM | Complete High School Maize |
| CHSS | California Home School Sports |
| CHSS | Cariboo Hill Secondary School |
| CHSS | Centre Hastings Secondary School |
| CHSS | Charles Hays Secondary School |
| CHSS | Clarkstown High School South |
| CHSST | Coronado High School Sailing Team |
| CHSW | Cranston High School West |
| CIASC | CSIR Innovation Award for School Children |
| CIASP | Childrens Initiatives After School Programs |
| CIASP | Chinese Immersion After School Program |
| CICS | Chicago International Charter School |
| CIEPSS | Curriculum Implementation in Early Primary Schools in Singapore |