| abb | AlphaBB Data |
| abbu | Mac OS X Address Book Backup |
| abc | ABC-View Manager Thumbnail Cache |
| abc | Act! Database Index |
| abc | Alembic Data |
| abcd | AudioVisual Book Data |
| abcddb | Apple Address Book Contact List Database |
| abcdmr | Apple Address Book Mail Recent Data |
| abcdp | Address Book CoreData Person Data |
| abd | Adventure Builder Data |
| abd | Intuit Quicken Address Book Add-on Data |
| abd | The Bat! Address Book |
| abdata | Adobe Bridge Keywords Database |
| abe | NoScript Application Boundaries Enforcer Data |
| abf | Microsoft SQL Server Analysis Services Backup Data |
| abf2 | Axon pCLAMP ABF2 Data |
| abicollab | AbiCollab Collaborative File Descriptor Data |
| abk | CorelDraw AutoBackup |
| abk | HP 95LX Appointment Book Data |
| abk | Kodak EasyShare Addressbook Data |
| abl | ADONIS Application Business Library |
| abl | Maxagrid Avails Data |
| abnf | Augmented Backus-Naur Form |
| abnf | jCard to vCard data |
| aboc | Edge Boundary Condition Data |
| abp | AVS Barcode Source Profile |
| abq | Abaqus/Explicit State Data |
| abs | Abscissa Data |
| abs | Absolute Database Data |
| abs | Avant Browser Skin Data |
