| Mobile Phonebook Format | |
| AT&T | |
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PBB file contains backup copy of mobile phonebook. Such backup copy is typically created at AT&T store by an employee. The backup procedure is conducted in order to backup contact data to a USB drive for the duration of phone maintenance, repairs, or phone replacement procedure.
Nowadays, the AT&T backup service is available as mobile app that synchronizes contacts. Accessing data stored in PBB file is possible by converting it into more popular CSV format.
| .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 |