| Abbreviation | Definition |
|---|---|
| CIP | Coordinated Instrument Package |
| CIP | Customer Integration Panel |
| CIR | Cargo Integration Review |
| CIR | Change Incorporation Record |
| CIR | CIRcle |
| CIR | CIRculate |
| CIR | Configuration Inspection Report |
| CIRA | COSPAR International Reference Atmosphere |
| CIRC | CIRCularization Burn |
| CIRC | Cross-Interleaved Reed-Solomon Code |
| CIRCUM | CIRCUMference |
| CIRHS | Critical Items and Residual Hazards List |
| CIRRIS | Cryogenic Infra-Red Radiance Instrument for Shuttle |
| CIS | Center for Internet Security |
| CIS | Central Integration Site |
| CIS | Change Impact Summary |
| CIS | Communication Interface System |
| CIS | Component Identification Sheet |
| CIS | Contractor's Information Submittal |
| CIS | Customer Information System |