| aqc | AquaChem Database |
| aqdb | ANSYS AQWAWB Database |
| aqe | AlpineQuest Elevation Data |
| aqg | BenMAP Air Quality Grid |
| aqm | AlpineQuest Map |
| Articulate QuizMaker Data |
| CP/M Information Data |
| PC 1000 Acquisition Method Data |
| aqp | Articulate Quizmaker 08 Quiz Data |
| aqr | PC 1000 Acquisition Result Data |
| aqtlb | TestComplete Toolbar Settings Data |
| aqz | Amateur Radio Zipped Questionary Data |
| ar-vmp | BrainVoyager QX Anatomical-resolution Volume Map |
| ar0 | MyDOS Ramdisk Image |
| ar1 | MyDOS Ramdisk Image |
| ar2 | MyDOS Ramdisk Image |
| ar3 | MyDOS Ramdisk Image |
| ar4 | MyDOS Ramdisk Image |
| ar4w | A Ruler For Windows Data |
| ar5 | MyDOS Ramdisk Image |
| ar6 | MyDOS Ramdisk Image |
| ar7 | MyDOS Ramdisk Image |
| ar8 | MyDOS Ramdisk Image |
| ar9 | MyDOS Ramdisk Image |
| ara | Archivaldo Resource Archive |
| ATI Radeon Video Driver ARA Data |
| arb | Alphacam Router VB Macro |
| arc | AMPAC Archive File |
| Orgadata LogiKal ARC Data |
| Tinker Archive |
| arca | RealityCharting Chart File |
| arcade | GameSpy Arcade Data |
| architect | BSS Soundweb London Design Data |
| arcinfo | ESRI ArcInfo Data |
| arcut | Adobe Prelude Rough Cut Data |
| arcutx | Adobe Prelude Rough Cut Data |
| ard | ArtiosCAD Workspace |
| arescol | Ares Galaxy Collection List |
| arexport | Spark AR Studio Export Data |
| arf | AOL Instant Messenger Resource Data |
| FITS Auxiliary Response Data |
| WebEx Advanced Recording |
| arff | Weka Attribute-Relation File Format |
| arfx | Spark AR Studio Effect Data |
| arg | Autodesk AutoCAD User Profile |
| arh | ArHymo Hydrologic Simulation Data |
| arlnk | Ares Galaxy Link Data |
| arlold | AOL Organizer Backup Data |
| arm | Alphacam Router Param Macro |
| Armadillo Protected File |
| ArmorPaint Asset Data |
| MySQL Archive Storage Engine Metadata |
| armodel | Kudan AR Model |
| aro | Autodesk Simulation Mechanical Reaction Force Output |
| arp | Adobe Audition Replay Data |
| Alphacam Router Post Data |
| AMS REALTIME Data |
| arpack | ArtRage Package File |
| arpatch | Spark AR Studio Patch Data |
| arr | Cubase VST Arrangement Data |
| Marvelous Designer Arrangement Point Data |
| Multimedia Fusion Array Data |
| ars | Adobe After Effects Render Settings |
| Artifax Event Report Editor Data |
| Corel WordPerfect Office Audio Data |
| arscript | ArtRage Script File |
| art | Alphacam Router Tool Data |
| Artifacts for Visual Studio Artifact Data |
| art70 | Bernina ArtLink v7 Embroidery Data |
| art80 | Bernina ArtLink v8 Embroidery Data |
| artborder | ArtBorder Data |
| artf | Adobe FreeHand Xtra Data |
| arti | Artizen HDR Data |
| artpro2 | Arturia Prophet V Data |
| artwork | iOS Artwork Data |
| artz | Adobe Illustrator for Mac Data |
| arv | CA Harvest SCM Data |
| Microsoft Autoroute User Data |
| arxml | AUTOSAR XML Data |
| arz | MySQL Archive Storage Engine Data |
