| 13o | RINEX Observation Data |
| 19o | RINEX Observation Data |
| 3dd | ArcGlobe Document |
| a2e | ArcGIS Option Data |
| adc | XMap Output Data |
| adf | ArcInfo Coverage Data |
| adp | SIA dataMap GIS Export |
| adrg | ARC Digitized Raster Graphics |
| afp | XMap Flight Plan Statistic Data |
| agf | ESRI Atlas GIS File |
| agr | ESRI ArcGIS Ascii Grid |
| agv | ArcGIS Video Metadata |
| aid | MapInfo Access ID File |
| aih | ArcGIS Optional Index |
| ain | ArcGIS Optional Index |
| alg | ER Mapper Algorithm Data |
| an1 | Street Atlas USA Draw File |
| anr | DeLorme Street Atlas Route Data |
| apr | ArcView Project |
| aprx | ArcGIS Pro Project |
| aptx | ArcGIS Pro Project Template |
| aqx | AlpineQuest XML Map |
| ard | Alan MAP 600 Map Data |
| asrp | Arc Standard Raster Product Data |
| at5 | Lowrance Sonar Raster Map |
| atf | SOCET SET Triangulation File |
| atx | ArcGIS Attribute Index |
| aux | ArcGIS Auxilliary File |
| ave | ArcView Avenue Script |
| avl | ArcView Legend Template |