| Abbreviation | Definition |
|---|---|
| POP | Problem Oriented Policing |
| POP | Problem-Oriented Policing |
| PR | Prosecutive Report |
| PRI | Potential Russian Informant |
| PRN | Puerto Rican Nationalist |
| PRNC | Potomac River Naval Command |
| PROSAB | PROtection of SAC (Strategic Air Command) Bases |
| PSI | Potential Security Informant |
| PSQ | Personnel Security Questionnaire |
| PTPU | Prosecution of Torture Perpetrators Unit |
| PV | Parole Violator |
| PX | Phoenix Field Office |
| R | Racial |
| R&I | Research and Investigation |
| R/S | Routing Slip |
| RA | Resident Agency |
| RAC | RACial Matters |
| RAIPE | Revolutionary Activities Informants Program Extremist |
| RCI | Reserve or Communist Index |
| RCMP | Royal Canadian Mounted Police |