| Abbreviation | Definition |
|---|---|
| PILF | Public Interest Law Foundation |
| PILG | Public Interest Liaison Group |
| PILI | Public Interest Law Initiative |
| PILI | Public Interest Law Institute |
| PILN | Public Interest Law Network |
| PILP | Public Interest Law Project |
| PIMP | Pucket Institute Of Medicine And Politics |
| PIN | People In Need |
| PINP | People In Need Partnership |
| PIOGA | Pennsylvania Independent Oil and Gas Association |
| PIP | Partners In Parks |
| PIP | Plant It Project |
| PIRG | Public Interest Research Group |
| PIRGIM | Public Interest Research Group In Michigan |
| PISA | Professional Investigators and Security Association |
| PISAD | Programme International de Sauvegarde de l'Amazônia, Mata Atlântica et des Amérindiens pour le Développement Durable |
| PISD | Rosa and Raymond Parks Institute for Self-Development |
| PISH | Partners In Senior Health |
| PIT | People For Interspecies Tolerance |
| PJ | Peninsula Jaycees |