| Abbreviation | Definition |
|---|---|
| ACSA | Airports Company of South Africa |
| ACSA | Airports Company South Africa |
| ACSA | Applied Computer Security Associates |
| ACSC | Advanced Casino Systems Corporation |
| ACSC | Anderson Community School Corporation |
| ACSC | Avon Community School Corporation |
| ACSI | Accell Corporate Sustainability Initiative |
| ACSI | Advanced Containment Systems Inc |
| ACSI | Advanced Cyclotron Systems Inc |
| ACSI | Affiliated Corporate Services, Inc. |
| ACSI | American Combustion Service Inc |
| ACSI | Approved Cylon Systems Integrator |
| ACSI | Architectural Control Systems Incorporated |
| ACSI | Architectural Control Systems, Inc. |
| ACSI | Argent Consulting Services, Inc. |
| ACSI | Automated Collection Services Inc |
| ACSI | Automated Conveyor Systems Inc |
| ACSU | Automation Customer Support Unit |
| ACT | Advance Clearing Transaction |
| ACT | Associated Consultants and Trainers |