| Abbreviation | Definition |
|---|---|
| CHW | Chicago White Sox |
| CI | Catcher Interference |
| CIBA | Champions International Baseball Academy |
| CIN | Cincinnati Reds |
| CLE | Cleveland Indians |
| CNBA | Central Nebraska Baseball Academy |
| CNBL | Calgary North Baseball League |
| CNLBR | Center for Negro League Baseball Research |
| COBA | Central Ontario Baseball Association |
| COL | Colorado Rockies |
| Coventry,RI | hi how are you what r u doing i am fine you are really nice with me |
| CPBA | Camarillo Pony Baseball Association |
| CPBL | Canadian Premier Baseball League |
| CPBL | Chinese Professional Baseball League |
| CPL | Coastal Plain League |
| CPY | Youth Catcher's Chest Protector |
| CS | Caught Stealing |
| CS | Caught Stealing percentage |
| CSP | Comfortable Starting Pitch |
| CTBA | Chinese Taipei Baseball Association |