| 1. | CAIBI | Conferencia de Autoridades Iberoamericanas de Informática |
| 2. | CALS | Computer-aided Adquisition and Logistic Support See also: USA |
| 3. | CARE | Sistema de alerta rápida y farmacovigilancia See also: IDA |
| 4. | CASE | Computer Assisted Software Engineering |
| 5. | CC.AA. | Comunidades Autónomas |
| 6. | CC.EE. | Comunidades Europeas |
| 7. | CCITT | Consultative Committee for International Telephony and Telegraphy |
| 8. | CCS | Comité de Coordinación de Normalización (Comisión Europea) |
| 9. | CD-ROM | Compact Disk - Read Only Memory |
| 10. | CDTI | Centro para el Desarrollo Tecnológico Industrial See also: MINER |