| Abbreviation | Definition |
|---|---|
| HYDX | Union Carbide Corporation (Praxair) |
| HYWX | Georgia Power |
| HZGX | Herzog Contracting Corporation |
| IAIS | Iowa Interstate Railroad |
| IAIS | Iowa Interstate Railroad Limited |
| IAIU | Intertronic Solutions |
| IALU | Japan Line |
| IALU | Japan Line Limited |
| IANR | Iowa Northern Railway |
| IANR | Iowa Northern Railway Company |
| IANW | Iowa Northwestern Railroad |
| IAPX | Air Liquide America Corporation |
| IAPX | Industrial Air Products (Air Liquide America Corporation) |
| IARO | International Air Rail Organisation |
| IASZ | Iowa Interstate Railroad |
| IASZ | Iowa Interstate Railroad Incorporated |
| IAT | Iowa Terminal Railroad |
| IAT | Iowa Terminal Railroad Company (formerly ITR) |
| IATR | Iowa Traction Railroad |
| IATR | Iowa Traction Railroad Company |