| Extension | File Description |
| .AOJ | Uncommon Files |
| .AOK | Uncommon Files |
| .AOL | Misc Files |
| .AOM | Settings Files |
| .AOMVER | Uncommon Files |
| .AON | Uncommon Files |
| .AOO | Uncommon Files |
| .AOP | Uncommon Files |
| .AOQ | Uncommon Files |
| .AOR | Uncommon Files |
| .AOS | System Files |
| .AOT | Uncommon Files |
| .AOU | Uncommon Files |
| .AOV | Uncommon Files |
| .AOW | Uncommon Files |
| .AOX | Uncommon Files |
| .AOY | Uncommon Files |
| .AOZ | Uncommon Files |
| .AP | Web Files |
| .AP0 | Uncommon Files |
| .AP1 | Uncommon Files |
| .AP2 | Uncommon Files |
| .AP3 | Uncommon Files |
| .AP4 | Uncommon Files |
| .AP5 | Uncommon Files |
| .AP6 | Uncommon Files |
| .AP7 | Uncommon Files |
| .AP8 | Uncommon Files |
| .AP9 | Uncommon Files |
| .AP? | Developer Files |
| .APA | Developer Files |
| .APB | Uncommon Files |
| .APC | Uncommon Files |
| .APD | Raster Image Files |
| .APE | Plugin Files |
| .APF | Audio Files |
| .APF2 | Uncommon Files |
| .APG | Uncommon Files |
| .APH | Data Files |
| .API | Settings Files |
| .APIN | Uncommon Files |
| .APJ | Uncommon Files |
| .APK | Executable Files |
| .APL | GIS Files |
| .APLN | Uncommon Files |
| .APLWRKS | Uncommon Files |
| .APLWRKSGS | Uncommon Files |
| .APM | Raster Image Files |
| .APN | Uncommon Files |
| .APO | Uncommon Files |
| .APP | Executable Files |
| .APPCACHE | Text Files |
| .APPL | Uncommon Files |
| .APPLE | Uncommon Files |
| .APPLE2 | Uncommon Files |
| .APPLESCRIP | Executable Files |
| .APPLESHARE | Uncommon Files |
| .APPLESOF | Uncommon Files |
| .APPLEWKS | Uncommon Files |
| .APPLICATIO | Settings Files |
| .APPLICATIO | Uncommon Files |
| .APPM | Uncommon Files |
| .APPREF-MS | Settings Files |
| .APPS | Uncommon Files |
| .APPT | Uncommon Files |
| .APQ | Uncommon Files |
| .APR | Developer Files |
| .APRJ | Uncommon Files |
| .APS | Raster Image Files |
| .APT | Uncommon Files |
| .APU | Uncommon Files |
| .APV | Uncommon Files |
| .APW | Uncommon Files |
| .APWKS | Uncommon Files |
| .APX | Raster Image Files |
| Extension | File Description |
| .APY | Uncommon Files |
| .APZ | Compressed Files |
| .AP_ | Developer Files |
| .AQ | Uncommon Files |
| .AQ0 | Uncommon Files |
| .AQ1 | Uncommon Files |
| .AQ2 | Uncommon Files |
| .AQ3 | Uncommon Files |
| .AQ4 | Uncommon Files |
| .AQ5 | Uncommon Files |
| .AQ6 | Uncommon Files |
| .AQ7 | Uncommon Files |
| .AQ8 | Uncommon Files |
| .AQ9 | Uncommon Files |
| .AQA | Uncommon Files |
| .AQB | Uncommon Files |
| .AQC | Uncommon Files |
| .AQD | Uncommon Files |
| .AQE | Uncommon Files |
| .AQF | Uncommon Files |
| .AQG | Uncommon Files |
| .AQH | Uncommon Files |
| .AQI | Uncommon Files |
| .AQJ | Uncommon Files |
| .AQK | Uncommon Files |
| .AQL | Uncommon Files |
| .AQM | Uncommon Files |
| .AQN | Uncommon Files |
| .AQO | Uncommon Files |
| .AQP | Uncommon Files |
| .AQQ | Uncommon Files |
| .AQR | Uncommon Files |
| .AQS | Uncommon Files |
| .AQT | Uncommon Files |
| .AQU | Uncommon Files |
| .AQV | Uncommon Files |
| .AQW | Uncommon Files |
| .AQX | Uncommon Files |
| .AQY | Uncommon Files |
| .AQZ | Uncommon Files |
| .AR | Compressed Files |
| .AR0 | Uncommon Files |
| .AR1 | Uncommon Files |
| .AR2 | Uncommon Files |
| .AR3 | Uncommon Files |
| .AR4 | Uncommon Files |
| .AR4W | Uncommon Files |
| .AR5 | Uncommon Files |
| .AR6 | Uncommon Files |
| .AR7 | Uncommon Files |
| .AR8 | Uncommon Files |
| .AR9 | Uncommon Files |
| .ARA | Uncommon Files |
| .ARB | Uncommon Files |
| .ARC | Backup Files |
| .ARCADE | Uncommon Files |
| .ARCANE | Uncommon Files |
| .ARCH | Uncommon Files |
| .ARCH00 | Game Files |
| .ARCHIE | Uncommon Files |
| .ARCHIMEDES | Uncommon Files |
| .ARCHITECT | Uncommon Files |
| .ARD | CAD Files |
| .ARE | Uncommon Files |
| .ARF | Video Files |
| .ARG | Settings Files |
| .ARGO | Uncommon Files |
| .ARH | Compressed Files |
| .ARI | Raster Image Files |
| .ARJ | Compressed Files |
| .ARK | Compressed Files |
| .ARK3 | Uncommon Files |
| .ARKCHEAT | Uncommon Files |
| .ARL | Settings Files |
| .ARLOLD | Uncommon Files |
