| Abbreviation | Definition |
|---|---|
| ACJU | American Coastal Lines Joint Venture |
| ACJU | American Coastal Lines Joint Venture Incorporated |
| ACL | Atlantic Coast Line Railroad (CSX Transportation) |
| ACL | Atlantic CoastLine |
| ACL | CSX Transportation Incorporated (Formerly Atlantic Coast Line) |
| ACLU | Atlantic Container Line |
| ACLU | Atlantic Container Line Limited |
| ACLX | American Car Line |
| ACLX | American Car Line Company |
| ACMX | Allis-Chalmers Corporation (Voith Hydro) |
| ACMX | Voith Hydro Incorporated |
| ACNU | AKZO Chemie B V |
| ACNU | AKZO Chemie, B V |
| ACOU | Associated Octel |
| ACOU | Associated Octel Company Limited |
| ACOX | Aurora Cooperative Elevator |
| ACPX | Amoco Canada Petroleum (Union Tank Car Lines) |
| ACPX | Amoco Oil Company |
| ACPZ | American Concrete Products |
| ACPZ | American Concrete Products Company |