| Abbreviation | Definition |
|---|---|
| PRDX | Pacific Rail Dismantling Services |
| PRDX | Pacific Rail Dismantling Services Incorporated |
| PREU | Prime Inc. |
| PREU | Prime Incorporated |
| PREX | Pioneer Railroad Equipment |
| PREX | Pioneer Railroad Equipment Company |
| PREZ | Prime Inc. |
| PREZ | Prime Incorporated |
| PRGX | Cargill Incorporated |
| PRGX | ProGold |
| PRI | Port Railroads Incorporated |
| PRIME | Platform of Rail Infrastructure Managers in Europe |
| PRL | Penn Eastern Rail Lines (East Penn Railway) |
| PRL | Penn Eastern Rail Lines Incorporated |
| PRLX | Private Rail Limited |
| PRLX | Progress Rail Services Corporation |
| PRMU | Puerto Rican Maritime Shipping Authority |
| PRMZ | Puerto Rican Maritime Shipping Authority |
| PROX | Procor |
| PROX | Procor Limited |