| Abbreviation | Definition |
|---|---|
| PPWCO | Pennsylvania Power Company (de-listed) |
| PPWCP | Pennsylvania Power Company Preferred |
| PPWCP | Pennsylvania Power Company Preferred (de-listed) |
| PPWCP | Pennsylvania Power Company Preferred (de-listed) |
| PPWLL | Pacificorp |
| PPWRL | Pacificorp of Oregon |
| PPWRM | Pacificorp |
| PPYM | Progressive Polymerics |
| PQBH | Pacific Mercantile Bank |
| PQUE | PetroQuest Energy, Inc. |
| PRAB | Prab, Inc. |
| PRAC | Productivity Technologies Corporation |
| PRAC | Productivity Technology Corporation |
| PRACW | Productivity Technologies Corporation Warrants (de-listed) |
| PRACW | Productivity Technologies Corporation Warrants (de-listed) |
| PRACW | Productivity Technology Corporation Warrants |
| PRAV | Paradigm Advanced Technology |
| PRBC | Prestige Bancorp, Inc. |
| PRBZ | ProBusiness Services, Inc. |
| PRCA | Packaging Research Corporation |