| jpm | Optifine JSON Part Model |
| jpn | PhotoModeler Lite Data |
| jpn | Unreal Engine Japanese Language Data |
| jpn | Windows Japanese Noise-word List |
| jpo | JPO Data |
| jpow | JPowered Java Bar Charts Data |
| jprint | JasperReports Print Object |
| jpx | jAlbum Image Info |
| jpz | Crossword Puzzle Solver Data |
| jqx | Windows Help Related Data |
| jqz | JQuiz Data File |
| jr6 | AGICO JR-6 Spinner Data |
| jra | AGICO JR-5 Spinner Data |
| jrb | OpenNMS JRobin Database |
| jrc | PCjr Cartridge ROM Image |
| jrd | OpenNMS JRobin Database |
| jrf | winIDEA Workspace Data |
| jrl | Top Secret Crypto Gold Journal Data |
| jrm | IBM Tivoli Resource Model Builder Data |
| jrmime | HDTracks Downloader Data |
| jrn | SAP POS Journal File |
| jrs | Microsoft Exchange Reserved Transaction Log |
| jrx | MDI DataScan Task List |
| js | Esko Automation Engine Job Sheet Data |
| jsd | Jazer Data File |
| jsd | JSDraw Data |
| jsda | Jazer Data File |
| jsdb | JumpStart Database |
| jsdraw | JSDraw Data |
| jsee | EmEditor Recorded Macro |
