| Abbreviation | Definition |
|---|---|
| CIRCA | Communication Information Resource Centre Administrator |
| CIREN | Crash Injury Research & Engineering Network |
| CIS | Career Information System |
| CISA | Certified Information System Auditor |
| CISO | Chief Information Security Officer |
| CISR | Certified Insurance Service Representative |
| CISSP | Certified Information Systems Security Professional |
| CIT | Camper In Training |
| CIT | Campus Instructional Technologist |
| CIT | Chefs In Training |
| CIT | Coach In Training |
| CIT | Coot In Training |
| CIT | Counselor In Training |
| CITM | Certified Information Technology Manager |
| CITRMS | Certified Identity Theft Risk Management Specialist |
| CITT | Canadian Institute of Traffic and Transportation |
| CIW | Certified Internet Webmaster |
| CIW | Illinois Central Railroad Company |
| CJE | Certified Jenkins Engineer |
| CJL | Certified Journeyman Locksmith |