| adidat | ADInstruments LabChart Simple Data |
| adif | Amateur Data Interchange Format File |
| adiumhtmllog | Adium HTML Log |
| adiumlog | Adium Chat Log |
| adix | XML-based ADIF File |
| adj | ADS40 Orientation Adjustment Data |
| adj | BenMAP Adjustment Factor File |
| adj | FARSITE Adjustment Factors Data |
| adj | LISCAD Adjustment Control Data |
| adjusted | PLINK Basic Multiple-testing Corrections Data |
| adl | ADONIS Exported Data |
| adl | DESQview ADL Data |
| adl | openEHR Archetype Definition Language File |
| adm | Addict Dictionary |
| adm | Advantage Database Server Memo Data |
| adm | Alphacam Diecut Param Macro |
| adm | Windows Administrative Template |
| adn | Lotus 1-2-3 Add-in |
| adn | Microsoft Access Blank Project Template |
| ado | Canvas Duotone Data |
| adobebridge | Adobe Bridge URL Data |
| adobenet | Adobe Production Studio Data |
| adp | Alphacam Diecut Post Data |
| adq | Microsoft Application Compatibility Toolkit Query Data |
| adr | After Dark Randomizer Data |
| adr | z-Tree Address Data |
| ads | ADS40 Header Data |
| ads | Agricultural Data Interchange Syntax File |
| adsklib | Autodesk Revit Material Library Data |
| adt | ABBYY Lingvo Custom Dictionary Text |
