| CI | Corporate Identity |
| GID | Group IDentity |
| EIR | Equipment Identity Register |
| LAI | Location Area Identity |
| CII | Call Identity Index |
| DAMI | Direct Access to Molecular Identity |
| ESDI | European Security and Defence Identity |
| TMSI | Temporary Mobile Subscriber Identity |
| IMSI | International Mobile Subscriber Identity |
| MMSI | Maritime Mobile Service Identity |
| SIM | SIM-Karte [Subscriber Identity Module] |
| IMEI | International Mobile Equipment Identifier/Identity |
| ISIC | International Student Identity Card Association Hamburg, http://www.isic.de |
| CN | Corporate Network |
| CTN | Corporate Telecommunication Network |
| CSR | Corporate Social Responsibilty soziale Verantwortung von Unternehmen |
| CPP | Corporate Preview Program |
| CPM | Corporate Performance Management |
| CNP | Corporate Network Provider |
| CMR | Corporate Message Recovery |
| CMC | Corporate Management Commitee |
| CD | Corporate Design [engl.] |
| CG | Corporate Governance [engl.] unternehmensweite Kontrolle |
| CAFE | Corporate Average Fuel Economy |
| MECN | Mobile Extended Corporate Network |
| CEP | Corporate Electronic Publishing [engl.] |
| CFM | Corporate Finance Management [engl.] Firmenbezeichnung [SAP] |
| GCCG | German Code of Corporate Governance http://www.gccg.de |
| CIIN | Corporate Integrated Information Network |
| CTOS | Corporate Telecommunications and Office Systems |
| CORNET | Corporate ISDN Network Protocol |
| CCDN | Corporate Consolidated Data Network [engl.] |
| CACG | Commonwealth Association for Corporate Governance [engl.] Marlborough, [NZ], http://www.cacg-inc.com |
| 3C | Corporate Airlines [IATA-Airline-Code/ USA] |
| QSIG | Unified International Corporate Network Signalling Standard |