| Abbreviation | Definition |
|---|---|
| CIPO | Commerce and intellectual property Office |
| CIPR | Coalition for Intellectual Property Rights |
| CIPRO | Companies Intellectual Property Registration Office |
| CIPU | Center for Intellectual Property Understanding |
| CIR | Claim Investigation Re |
| CIRAS | Crime Information Reporting and Analysis System |
| CIRN | Criminal Investigation Research Network |
| CIRT | Court Intervention Response Team |
| CIS | Case Information Study |
| CIS | Corruption is Systemic |
| CIS | Court Information System |
| CIS | Criminally Insane Snipers |
| CISC | Criminal Intelligence Service Canada |
| CISC | Criminal Intelligence Service of Canada |
| CISOCA | Centre for Investigation of Sexual Offences and Child Abuse |
| CISS | Crash Investigation Sampling System |
| CITA | Corporate Income Tax Act of 1969 |
| CITC | Conspiracy in the Court |
| CITED | Copyright In Transmitted Electronic Documents |
| CITF | Criminal Investigation Task Force |