| jpa | Akeeba Multi-part Backup Archive |
| jpa | JoomlaPack Backup Archive |
| jps | Akeeba Secured Backup Archive |
| jp_ | Compressed Microsoft JPEG Image |
| jrc | JRchive Data |
| jsonlz4 | Mozilla Firefox Compressed Bookmarks Backup |
| jva | Junos Firefly VM Package |
| jzip | JZip Archive |
| kb2 | Kleo Backup Archive |
| kde | Kaspersky KryptoStorage Container |
| kdz | LG Smartphone Firmware Update |
| keb | Kaspersky Anti-virus Virus Bases Data |
| kgb | KGB Compressed Archive |
| kge | KGB Archiver Encrypted |
| knar | KNIME Workflow Archive |
| kodi | Kodi Update Data |
| kry | Krypter Encrypted Data |
| ksp | KeyShot Package |
| kva | KVIrc Compressed Archive |
| kwt | KVIrc Theme Pack |
| kz | KuaiZip Compressed File |
| lal | Liberkey Core Update File |
| lbf | LG Phone Backup Archive |
| lbr | LU Library Archive |
| lcb | Living Cookbook Backup |
| lemon | LemonShare.net Download |
| lg | Arhangel Compressed Archive |
| lgbackup | LG G7 Phone Backup Archive |
| lgu | LG Windows CE Device Firmware Update |
| lgu | Renault R-Link Firmware Update Package |
