| p4 | Perforce P4 Data |
| p4thor | Thor Exported Packet Records Data |
| p5m | PyMOL P5M Script |
| p7a | PKCS #7 Attached Signature |
| p7b | PKCS #7 Certificate Data in Base 64 Format |
| p7c | PKCS #7 Certificate Data |
| p7d | PKCS #7 Detached Signature |
| p7e | File Encryptor Encrypted Data |
| p7m | PKCS #7 Encrypted Message |
| p7mkey | KeePass Certificate-protected Key |
| p7r | PKCS #7 Certificate Request Response File |
| p7s | PKCS #7 Digital Signature |
| p7x | Windows SDK Packed Digital Signature |
| p7z | PKCS #7 Compressed Message |
| p8 | PICO-8 Data |
| p83 | GAEB DA 2000 Data File |
| p99 | MicroStation Modification Project Resource File |
| pa2 | CME SPAN Expanded Format Data |
| pa2m | SAM PA2M Alignment Data |
| pab | Microsoft Outlook Personal Address Book |
| pad | Portable Application Description |
| pafsc | Esko LinkEdge Package |
| pai | PocketAI Data File |
| paltalk | Paltalk Data |
| pamp | Poweramp Album Thumbnail |
| pan | Panorama Database File |
| panic | Mac OS X Kernel Panic Data |
| pao | Xilinx Peripheral Analyze Order File |
| pap | Corel Painter Paper Texture |
| papers | Corel Painter Paper Texture |
| par | Mail.dat Postage Adjustment File |
| param | CASTEP Parameters Data |
| parca | RealityCharting Packaged Chart |
| part2 | NetObjects Fusion Internal System Data |
| part3 | NetObjects Fusion Internal System Data |