| Abbreviation | Definition |
|---|---|
| ICSI | Institute of Company Secretaries of India |
| ICSI | Integrated Circuit Solution Incorporation |
| ICSI | International Computer Services Incorporated |
| ICSID | International Centre for Settlement of Investment Disputes |
| ICSL | Clinical Studies Ltd |
| ICSL | Information Connectivity Solutions Limited |
| ICSL | International Communication Services, Limited |
| ICSL | International Company Services Ltd |
| ICSL | Inuit Communications Systems LTD. |
| ICSM | Internet Communication Services Mauritius |
| ICSN | Immigration Consultant Support Network |
| ICSO | International Company Secretaries Olympiad |
| ICSO | International Container Security Organization |
| ICSP | Institute of Corporate Secretaries of Pakistan |
| ICSP | International Customer Service Professionals |
| ICSP | Internet and Computer Service Provider |
| ICSS | Deutsche Telekom International Carrier Sales & Solutions |
| ICSS | I&C Systems Integrator & Service Company, Inc. |
| ICST | Institute of Circulation System Technology corporation |
| ICST | Intra Company Stock Transfer |