| Abbreviation | Definition |
|---|---|
| PCB | Polychlorinated Biphenyl |
| PCC | Policy Coordination Council |
| PCGRIDS | Personal Computer Gridded Interactive Display and Diagnostic System |
| PCMDI | Program for Climate Model Diagnosis and Intercomparison |
| PCMI | President's Council on Management Improvement |
| PCR | Polymerase Chain Reaction |
| PCS | Permanent Change of Station |
| PCSD | President's Council on Sustainable Development |
| PCT | Peru Chile Trench |
| PD | Position Description |
| PDAS | Photodiode Array Spectrophotometer |
| PDC | Pacific Disaster Center |
| PDO | Pacific Decadal Oscillation |
| PDP | Program Development Plan |
| PED | Pressure Equipment Directive |
| PEER | Pacific Earthquake Engineering Research |
| PEMT | Pacific Exploratory Mission Tropics |
| PEM-WEST | Pacific Exploratory Mission-West |
| PEN | Pacific Exchange Network |
| PENTAFLUX | Fifth Flux Experiment |