| Abbreviation | Definition |
|---|---|
| PIMRC | Petaluma International Military Research Center |
| PIN | Personal Identification Number |
| PIN | Personnel Increment Number |
| PIN | Personnel Item Number |
| PIN | Plan Identification Number |
| PING | Packet InterNet Grouper |
| PINKO | Communist |
| PINS | Person In Need Of Supervision |
| PINS | Precise Integrated Navigation System |
| PINS | Project Initiation Notification System |
| PIO | Press Information Officer |
| PIOS | Programmable Integrated Ordnance Suite |
| PIOTA | Pull It Out of The Air |
| PIP | Participant Instrumentation Package |
| PIP | Priority Improvement Project |
| PIP | Product Improvement Program (or Plan or Proposal) |
| PIP | PTC (Pentagon Telecommunications Center) Interface Processor |
| PIP | PTC Interface Processor |
| PIPS | Personnel Investigation Processing System |
| PIPS | Plans Integration Partitioning System |