| Abbreviation | Definition |
|---|---|
| CIS | Critical Information Shortfall |
| CISAM | Centro Interforze Studi Applicazioni Militari |
| CISCO | Corps Information Systems Control Officer |
| CISD | Canadian Industrial Security Directorate |
| CISD | Critical Incident Stress Debriefing |
| CISF | Central Industrial Security Force |
| CISO | Chief Information Security Officer |
| CISO | Counter-Intelligence Staff Officer |
| CISP | Counter-Intelligence Support Plan |
| CISPO | Combat Identification Systems Project Office |
| CISS | Center for Information Systems Security |
| CITIS | Contractor Integrated Technical Information Service |
| CITP | Counter-IED (Improvised Explosive Device) Targeting Program |
| CITS | Combat Information Transport System |
| CITV | Commander's Independent Thermal Viewer |
| CIU | Cell Interface Unit |
| CIU | Communications Interface Unit |
| CIUS | Corps Interim Upgrade System |
| CIV | Civilian |
| CIVMIL | Civil Military |