| Abbreviation | Definition |
|---|---|
| COSAL | Conference on South Asian Literature |
| COSCA | Conference of State Court Administrators |
| COSIT | Conference On Spatial Information Theory |
| COSM | Combined Otolaryngological Spring Meetings |
| COSM | Conference On Software Maintenance |
| COSP | Conference of State Parties |
| COSP | Conference of States Parties |
| COSP | Conference of the States Parties |
| COSSH | Congress Of the Social Sciences and Humanities |
| COTB | Conference Of The Birds |
| COTC | Chiefs of Transformation Conference |
| COWE | Confederation Of Women Entrepreneurs |
| COWL | Conference of Women Legislators |
| COWR | Conference on Writing Research |
| COY | Conference of Youth |
| COYA | Conference of Young Alaskans |
| CPAC | Central Plains Athletic Conference |
| CPAC | Conservative Political Action Conference |
| CPAK | Conference on Precession and Ancient |
| CPAK | Conference on Precession and Ancient Knowledge |