| Abbreviation | Definition |
|---|---|
| AKC | Arkansas Central Railroad |
| AKDN | Acadiana Railway |
| AKDN | Acadiana Railway Company |
| AKFX | AKF Corporation |
| AKIBA | Akihabara |
| AKLU | K Line |
| AKLU | Kawasaki Kisen Kaisha (K Line) |
| AKMD | Arkansas Midland Railroad |
| AKMD | Arkansas Midland Railroad Company |
| AKMX | A&K Railroad Materials (Helm Financial Corporation) |
| AKMX | Helm Financial Corporation |
| AKZX | Akzo Nobel Chemicals |
| AKZX | AKZO Nobel Chemicals Incorporated |
| AKZX | Azko Nobel Chemicals |
| AL | Almanor Railroad |
| AL | Almanor Railroad Company |
| AL&G | Arkansas, Louisiana and Gulf Railway |
| ALAB | Alabama Railroad |
| ALAB | Alabama Railroad Company |
| ALAX | Alaska Asphalt (Equistar Chemicals) |