| Backup Plus Backup Format | |
| N/A | |
| Ads |
File with a .BKUP extension contains a backup copy of a different types of files, utilised by different types of software or scripts. It is not specific to any program, it is a general extension.
BKUP files can comprise of a copy of important files or for example server logs. Backup copies are used when the original file is damaged or deleted.
Linux
| .ab | Google Android Debug Bridge Backup Format |
| .aba | Palm Address Book Archive Format |
| .abbu | Apple Address Book Archive Format |
| .abf | Adobe Binary Screen Font Format |
| .abk | Ability Write Backup Format |
| .acp | Alfresco Exported Repository Format |
| .adi | Active@ Disk Image Format |
| .aea | Ae Timer Alarm Document Format |