| Abbreviation | Definition |
|---|---|
| CIS | Corporate Identity System |
| CIS | Customer Information System |
| CISC | Computer Information Storage Center |
| CISC | Customer Information Control System |
| CISO | Computer Information Systems Organization |
| CISVP | Catalog Information Systems Vendor Program |
| CIT | Communications And Information Technology |
| CITE | Construction Industry Trading Electronically |
| CITP | Canadian Industrial TEMPEST Program |
| CIVETS | Colombia, Indonesia, Vietnam, Egypt, Turkey, South Africa |
| CIWT | Compact Implementation Writing Team |
| CJ | Commission Junction |
| CJI | Computer Jobs in Israel |
| Ck | check / cheque |
| CK | Cvitani'c and Karatzas economic consumption theory |
| CKA | Consumer Knowledge Analysis |
| ckd | checked |
| CL | Company Logo |
| CLA | Collective Labor Agreement |
| CLAP | Computerized Leave Accounting Package |