| adidat | ADInstruments LabChart Simple Data |
| adif | Amateur Data Interchange Format File |
| adiumlog | Adium Chat Log |
| adix | XML-based ADIF File |
| adj | BenMAP Adjustment Factor File |
| adj | FARSITE Adjustment Factors Data |
| adj | ADS40 Orientation Adjustment Data |
| adj | LISCAD Adjustment Control Data |
| adl | openEHR Archetype Definition Language File |
| adm | Alphacam Diecut Param Macro |
| adm | Windows Administrative Template |
| adm | Addict Dictionary |
| adn | Microsoft Access Blank Project Template |
| adp | Alphacam Diecut Post Data |
| adq | Microsoft Application Compatibility Toolkit Query Data |
| adr | z-Tree Address Data |
| adr | After Dark Randomizer Data |
| ads | ADS40 Header Data |
| ads | Agricultural Data Interchange Syntax File |
| adsklib | Autodesk Revit Material Library Data |
| adt | Alphacam Diecut Tool Data |
| adt | Act! Template |
| adtg | Microsoft Advanced Data TableGram Data |
| adu | Addict Custom Dictionary |
| adups | Android Update Data |
| adw | Adhawin Transliteration Scheme |
| adx | XML-based ADIF File |
| ad_pcf | Alibre Design Catalog Feature Part Data |
| ad_smp | Alibre Design Sheet Metal Parts Data |
| ad_sym | Alibre Design Symbols Data |
