| pro | FEMFAT Result Protocol Data |
| pro | PATCHMASTER Protocol Editor Information |
| pro6plx | ProPresenter 6 Exported Playlist |
| prob | PLINK Meta-analysis Rejected Variant List |
| prof | D-Fend Reloaded Profile Data |
| progression | Akai MPC Software Progression Data |
| proj | Poseidon for UML Project Information |
| promizer | Promizer Data |
| prop | STK Propulsion for AMM File |
| prot | XEASY Chemical Shift List |
| protdb | Skyline Spectral Library Explorer Proteome Database |
| prox | POV-Ray DF3 Proximity Pattern Parameters |
| prp | Kodak Preps Data |
| prpt | Pentaho Reporting Archive |
| prr | Accent Office Password Recovery Data |
| prs | CorelDraw Print Style |
| prsl | Adobe Premiere Style Library Data |
| prt | BrainVoyager QX Protocol Data |
| prt | PTC Creo Part Data |
| prtc | OmniPage PRTC Data |
| prtdot | SolidWorks Part Template |
| prtprp | SolidWorks Parts Properties Template |
| pru | IBM Tivoli Storage Manager Pruned Entry Data |
| prv | Windows Previous Bootlog File |
| prvkr | PGP Private Keyring Data |
| prw | Artlantis Shader Preview |
| prwm | Packed Raw WebGL Model Data |
| prx | Lucene Positions File |
| prz | NI Multisim Packed Component Data |
| ps | ETCBC Phrase Structure Data |
| ps1 | ETCBC Phrase Structure Data |
| ps2 | ETCBC Word Parsing Data |
| ps3 | ETCBC Phrase Structure Data |
| ps4 | ETCBC Phrase Structure Data |
| ps7 | Corel Paint Shop Pro Data |