| $ | Visual Basic Symbols Data |
| $$m | 3D Gamestudio Backup Map Data |
| $01 | DOS Pipe File |
| $b | TR-DOS Basic Data |
| $dx | CA Visual Objects Index Backup |
| 1st | Visual FoxPro Documenting Wizard List |
| 1t | Fortran 1T Data |
| 2clk | Frontier for Mac Script |
| 2la | 2LANG Data |
| 2lang | 2LANG Data |
| 33b | SYNETSIM QuickBasic Source Code |
| 3dfbat | 3DField Script |
| 3dmlw | 3D Markup Language for Web Document |
| 3mp | TTCN-3 Source Code |
| 3xe | 3DLinX Entity Data |
| 42m | Genero BDL Compiled Module |
| 4da | 4D User Forms Data |
| 4ge | IBM Informix 4GL Compiled Code |
| 4gl | IBM Informix 4GL Source Code |
| 4ma | FileMaker Pro Runtime Database |
| 4th | Forth Source Code |
| 4ui | ForeUI Plot |
| a | Ada Source Code |
| Free Pascal Archive |
| a1 | Free Pascal Compiled Archive |
| OpenEdge ABL After Image |
| a2 | OpenEdge ABL After Image |
| a31 | Adobe Authorware Library |
| a3c | Alan v3 Adventure Code |
| a3l | Adobe Authorware Library |
| a3m | Macromedia Authorware Macintosh File |
| a3w | Macromedia Authorware Windows File |
| a3x | AutoIt v3 Compiled Script |
| a41 | Adobe Authorware Library |
| a43 | IAR System MSP430 Target Application |
| a4e | Adobe Authorware External Library |
| a4l | Adobe Authorware Library |
| a4m | Macromedia Authorware Macintosh File |
| a4p | Macromedia Authorware Source |
| a4w | Macromedia Authorware Windows File |
| a51 | Adobe Authorware 5.1 Library |
| µVision Assembler Source Code |
| a5l | Adobe Authorware Library |
| a5m | Macromedia Authorware Macintosh File |
| a5p | Macromedia Authorware Source |
| a5rpt | Alpha Five Project Report |
| a5w | Alpha Five Web Publishing File |
| Macromedia Authorware Windows File |
| a5wcmp | Alpha Five Web Publishing Component |
| a65 | Adobe Authorware 6.5 Library |
| a66 | µVision Assembler Source Code |
| a68 | PDP-10 Algol-68 Compiler Source Code |
| a6l | Adobe Authorware Library |
| a6m | Macromedia Authorware Macintosh File |
| a6p | Macromedia Authorware Source |
| a6w | Macromedia Authorware Windows File |
| a7e | Macromedia Authorware Packaged Library |
| a7l | Adobe Authorware Library |
| a7m | Macromedia Authorware Macintosh File |
| a7p | Macromedia Authorware Source |
| a7w | Macromedia Authorware Windows File |
| a86 | A86 Assembly Source Code |
| aah | Amazingly Abstracted HTML Document |
| aapkg | ArchestrA IDE Package |
| aas | Windows Application Assignment Script |
| ab | Android Debug Bridge Backup |
| Applix Builder Data |
| ab2 | Blitz Basic Code |
| abap | ABAP Source Code |
| abc | Adobe ActionScript Bytecode |
| LithTech 3D Game Model |
| abex | Enhanced Android Backup |
| abl | ABEL Hardware Description Language Data |
| abm | Alpha Five Database Export |
| abn | Alpha Five Database Export |
| abo | Applix Builder Object |
| abs | Atari Jaguar DRI/Alcyon Format Data |
| GCC ELF/DWARF Format Absolute Data |
| ac | GNU Autoconf Input File |
| accessor | Visual Studio Accessor Data |
| acl | Arbortext Command Language Data |
| acme | ACME Assembler Source Code |
| acsup | Avaya CMS Script |
| act | DS Game Maker Action Data |
| Visual FoxPro Documenting Wizard Action Diagram |
| actionscript | Adobe Flash ActionScript |
| actx | DS Game Maker Action Description |
| acu | ACUCOBOL-GT Compiled Program |
| acx | IBM Rational XDE ACX Data |
| WebFOCUS Data Description |
| ad | AxSys Script |
| DSM Application Diagram |
| ada | Ada Source Code |
| adb | Ada Implementation File |
| Alpha Five Database |
| adblock | Alpha Five Database Lock |
| adcp | Adobe Device Central Project |
| add | Apache Beehive Collection Data |
| addin | Visual Studio Add-in Definition |
| adi | Microsoft Dynamics AX Application Developer Documentation Index |
