| pj2 | Project64 Saved State File |
| pjb | IBM InfoSphere Information Server Manager Data |
| pjd | Portfolio Exported Categories Data |
| pjf | Photojunction File |
| pjf | iAddress Postal Job File |
| pjl | HP Printer Job Language Data |
| pjnz | Spectrum Projection Data |
| pjtf | Portable Job Ticket Format Data |
| pjv | Velocity User Selections Data |
| pk | Adobe Audition v3 Peak File |
| pka | Cisco Packet Tracer Activity File |
| pkb | Blackberry Password Keeper Encrypted Backup |
| pkb2 | Blackberry Password Keeper Encrypted Backup |
| pkc | Jython JAR Cache |
| pkcs12 | PKCS #12 Data File |
| pkcs7 | PKCS #7 Certificate Data |
| pkd | Eurotherm Encrypted Hydra History Data |
| pkf | Adobe Audition Peak File |
| pkgx | Microsoft UE-V PKGX Data |
| pki | LibVirt PKI Data |
| pkj | PokerJuice Data |
| pkl | Migration Wizard Packing List File |
| pkn | Microsoft SMS Package Creation Notification |
| pkr | PGP Public Keyring File |
| pks | STOE Powder Diffraction Peak Data |
| pkt | Cisco Packet Tracer Network Simulation Model |
| pku | FidoNet Batched Newsgroup Data |
| pkw | CabnetWare Package |
| pky | PockeTTY Security Certificate |
| pl3 | Pathloss Link Design Data |
| pl3 | Harvard Graphics ChartXL Palette Data |
| pl4 | Micrografx Designer 4.0 Palette |
| pl4 | Pathloss Link Design Data |
| pl5 | Pathloss Link Design Data |
| plb | Microsoft Robotics Developer Studio Playback Data |