| pri | LocoScript Printer Definition Data |
| pri | Migration Wizard Primary IFF File |
| pri | Primo Emulator Image |
| pri | Source Insight Symbol Index |
| printerexport | Windows Printer Migration Data |
| priv | Splinter Private Key |
| private | OpenSSL Private Key Data |
| prj | Binary Terrain Data |
| prj | ESRI ArcInfo Projections Definition Data |
| prjm | projectM Music Visualizer Preset |
| prk | Campground Master Database |
| prl | Corel Paint Shop Pro Rough Leather Preset |
| prl | E-Sword v8 Prayer Request |
| prl | PRELIS Syntax Data |
| prl8 | 3D Proliner Measurement Data |
| prlgpreset | Korg Prologue Preset Collection |
| prlx | E-Sword v9 Prayer Request |
| prm | Bosch VisualMotion System Data |
| prm | MicroImages TNT Parameters Data |
| prm | Raynen-Qili KnitCAD Pattern Cycle Data |
| prm | TINA Pro Analyses Control Parameter File |
| prm | Tinker Parameter File |
| prmdc | Adobe Premiere Metadata Cache |
| prmdc2 | Adobe Premiere Metadata Cache |
| prn | CRiSP Harvest Print Data |
| prn | SmartWare Print Data |
| prnt | OnScale Designer Output Data |
| prnx | XtraReports PrintingSystem Document |
| pro | Carlson 2015 Profile Data |
| pro | Carlson 2016 Profile Data |
| pro | COREX Prosodic Annotation Data |
| pro | FEMFAT Result Protocol Data |
| pro | PATCHMASTER Protocol Editor Information |
| pro | Pegasus Mail POP Profile Data |
| pro | Power Render Object |
