File extensions are often used to determine the program that created the file. While there is no guarantee users will not rename files and/or associate odd extensions with particular programs, the following are some fairly standard associations.

  .###  Temporary File  
  .#24  Locoscript 24-pin Printer Data File
  .#IB  Locoscript Dot Matrix Data File
  .#SC  Locoscript Dot Matrix Data File
  .#ST  Locoscript Dot Matrix Printer Definition File

  .$$$  Temporary File (various)
  .$$A  OS/2
  .$$F  OS/2 Database
  .$$P  OS/2 Notes
  .$$S  OS/2 Spreadsheet
  .$D$  OS/2 Planner Data File
  .$DB  dBase Temp File
  .$ED  MS C/C++ Temporary Editor File
  .$LN  Borland C++ TLink Response File
  .$VM  MS Windows Virtual Manager Temp File

  .@@@  Screen Files (shown during various installations) 

  ._DD  Norton Disk Doctor Recovered File
  ._DM  Nuts n Bolts Disk Minder Recovered File (Helix Software now part of McAfee)

  .000  (000-999) Sequentially Numbered Backup Files
        MS Doublespace Compressed Data File
        Geoworks Data File
  .001  Fax Data File (various)
  .075  Ventura Publisher 75dpi Screen Characters
  .085  Ventura Publisher 85dpi Screen Characters
  .091  Ventura Publisher 91dpi Screen Characters
  .096  Ventura Publisher 96dpi Screen Characters
  .0B   PageMaker Printer Font LineDraw Characters

  .10X  Gemini Bitmap Printer Graphics File
  .113  Iomega Backup File
  .123  Lotus File
  .12M  Lotus Smartmaster File
  .12U  PageMaker Font File
  .15U  PageMaker Printer Font
  .196  Computer Snooper Log File
  .1PE  TurboTax Form File
  .1ST  Information (e.g., README.1ST)

  .24B  24-bit Graphic File
  .286  Windows Standard Mode Driver
  .2D   2D VersaCAD Drawing File
  .2GR  Windows EGA/VGA Screen Grabber

  .301  Fax Data
  .303  Seq-303 Settings
  .320  Chromelion Demo Data File
  .323  H.323 Internet Telephony
  .340  Chromelion Demo Data File
  .386  Windows Enhanced Mode Driver or Swap File
  .3D   VersaCAD 3D Drawing File
  .3DM  3D Modeler File
  .3DP  Serif 3D Plus
  .3DS  3D Studio Graphic
  .3FX  Corel Chart 3D Effect
  .3GR  Windows SVGA/XVGA Screen Grabber
  .3IN  MSN Setup Information

  .411  Sony Mavica Data File
  .4GE  Informix 4GL Compiled Code
  .4GL  Informix 4GL Source
  .4SW  4DOS Swap File
  .4TH  FORTH Program
  .4V   Quartet Music File

  .669  669 Tracker Module
        Unis Composer Music File

  .8    A86 Assembler Program File
  .8BA  Adobe PhotoDeluxe Plugin (also ends in E, F, I, X, & Y)
  .8BF  Filter Factory File  [Added]  [Viewer]
  .8M   PageMaker Math 8 Printer Font
  .8U   PageMaker Roman 8 Printer Font

  .906  Calcomp Plotter File

  .?q?  Squeeze
  .???  ANY three character audio file: May be a dictation file where the
        extension is the dictator's initials; playable by BCB Voice Systems

  .A    UNIX Library
        ADA Program
  .A01  ARJ Multi-volume Compressed Archive (can be 01 to 99)
  .A11  Graphic
  .A3K  Yamaha A3000 Sampler File
  .A3L  Authorware 3.x Library
  .A3M  Unpackaged Authorware MacIntosh File
  .A3W  Unpackaged Authorware Windows File
  .A4L  Authorware 4.x Library
  .A4M  Unpackaged Authorware MacIntosh File
  .A4P  Authorware File Without Runtime
  .A4W  Unpackaged Authorware Windows File
  .A5L  Authorware 5.x Library
  .A5W  Unpackaged Authorware Windows File
  .A86  A86 Assembler Program File
  .A_T  A-Train  
  .AA   Audio Book File
  .AAM  Authorware Shocked File
  .AAS  Authorware Shocked Packet
  .AB   Applix Builder File
  .AB6  AB Stat Data
  .AB8  AB Stat Data
  .AB$  AutoCAD Spooled Plot File
  .ABC  Flowchart
  .ABD  AmBiz Bonus Calculator Data File
  .ABF  Adobe Binary Screen Font
  .ABK  Corel Draw AutoBackup
        Any Automatic Backup
  .ABM  HitPlayer Audio Album File
        Album File (various)
  .ABO  Applix Builder Turbo File
  .ABR  Photoshop Brush
  .ABS  Abstracts
        MPEG Audio Sound File
        PC GNU Compiler Output
        Abscissa Data File
  .ABW  AbiWord Document File
  .ACA  MS Agent Character File
        Project Manager Workbench File
  .ACB  ACBM Graphic Image
        Archived Data File
  .ACC  DR-DOS Viewmax File
  .ACD  Chromeleon Channel Raw Data
        Sonic Foundry Acid Music File
        MS Agent Character Definiton File
  .ACE  The Ace Archiver Compressed File
  .ACF  MS Agent Character File
        Photoshop Custom Filter
  .ACG  MS Agent Preview File
  .ACI  ACI Development Appraisal
  .ACL  Corel Draw 6 Keyboard Accelerator
  .ACM  Audio Compression Manager Driver (Windows)
        Photoshop Command Button
        Windows System File
        ACBM Image File
        Interplay Compressed Sound File
  .ACO  Photoshop Color Swatch File
  .ACP  MS Office Assistant Preview File
  .ACR  American College of Radiology File
  .ACS  MS Agent Character File
  .ACT  MS Office Actor Program File
        FoxPro Documenting Wizard Action Diagram
        Photoshop Color Table
  .ACV  OS/2 Audio Drivers
        Photoshop Saved Curve  Also see
  .AD   AfterDark Screen Saver

  .ADA  ADA Program File
  .ADB  ADA Package Body
        HP Organizer Appointment Database
  .ADC  Chromeleon Demo Data File
        Scanstudio 16-color Bitmap Graphic File
        Lingvo Dictionary Text File
  .ADD  OS/2 Adapter Device Driver
        Adobe Pagemaker File
  .ADE  MS Access Project Extension
        ADC Audio File
  .ADF  Adapter Description File
        Admin Config File
        Amiga Disk File (Uncompressed 901120 byte DD Diskimage)
  .ADI  AutoCAD Plotter File
  .ADL  QEMM MCA Adapter Description Library
  .ADM  After Dark Screen Saver Module
        Windows NT Policy Template
  .ADN  1-2-3 Add In Utility
        MS Access Blank Project Template
  .ADO  Photoshop Duotone Options
  .ADP  FaxWorks Modem Setup File
        Astound Dynamite File
        MS Access Project
        AOLserver Dynamic Page File
  .ADR  After Dark Random Screen Saver Module
        Smart Address Address Book
  .ADS  ADA Package Specification
  .ADT  HP NewWave Card Application Data File
        Lingvo Dictionary File
        AdTech Fax File
  .ADV  GUS Virtual Device Driver
  .ADX  Lotus Approach Index File
        Archetype Designer Document
        Dynazip Active Delivery Script
  .ADZ  GZ-Packed Amiga Disk File (see ADF)
  .AE   SoftQuad Author/Editor File
  .AEH  iPer Advanced Embedded Hypertext
  .AEP  ArcExplorer Project File
  .AEX  PGP Armored Extracted Public Encryption Key
  .AF2  ABC Flowchart (Now Micrografx FlowCharter)
  .AF3  ABC Flowchart (Now Micrografx FlowCharter)
  .AFC  Apple Sound File
  .AFI  Truevision Bitmap Graphic
  .AFL  Lotus Font
  .AFM  Outline Font Metric
        HP NewWave Cardfile Application
  .AFP  Flowchart Symbol Palette  
  .AFS  Filter Factory Photoshop Filter  [Added]
  .AFT  Flowchart Template
  .AFW  Flowchart Work Area
  .AG   Applix Graphic
  .AG4  Access G4 File
  .AHS  Photoshop Halftone Screens
  .AI   Adobe Illustrator Vector Graphic
        Corel Trace Drawing
        Progress Database After Image File
  .AIF  Knowledgeware Setup Information
        Audio Interchange File  [Viewer]  
  .AIM  AOL Instant Messenger File 
  .AIN  AIN Compressed Archive
  .AIO  APL File Transfer Format
  .AIR  Align It! Resource File
  .AIS  Array of Intensity Samples (Graphic)  
        Velvet Studio Instruments
        ACDSee Image Sequence File
  .AIX  HP NewWave Cardfile Application Data
  .AKF  Acrobat Key File
  .AKW  RoboHELP Help Project Index File
  .ALB  JASC Image Commander Album
  .ALC  Norton Internet Security Ad Server File

  .ALL  Arts & Letters Symbols and Characters
        WordPerfect Printer Info
  .ALS  Alias Image
  .ALT  WordPerfect Menu File
  .ALV  Photoshop Levels
  .AM   Applix SHELF Macro
  .AMF  Advanced Module Format Music File
        DSMIA/Asylum Module Music 
  .AMG  AMGC Compressed Archive (alternate site)
        AMG ACTOR System Image
  .AMI  Cocreate SolidDesigner Annotation File
  .AMP  Photoshop Arbitrary Map Settings
  .AMS  Extreme's Tracker Module Format
        Photoshop Monitor Setup
        Velvet Studio Module
  .AN   Groundworks Text File 
  .ANC  Canon Computer Pattern Maker File
  .ANI  Animated Cursor  [Viewer]
  .ANL  Project Analyzer Saved Analysis
  .ANM  DeluxPaint Animation
  .ANN  Help Annotation
  .ANS  ANSI Graphic
        MS Word Text and Layout
  .ANT  SimAnt for Windows Saved Game File
  .AOS  Nokia Add-on Software
  .AOT  ZenWorks Application Binary Object Template File
  .AP   Applix Presents File
        WHAP-Compressed Amiga Archive
  .APC  Lotus Printer Driver Characters
        Centura Team Developer Compiled Application File
  .APD  Lotus Printer Driver
        Centura Team Developer Dynamic Application Library File
  .APF  Lotus Printer Driver Fonts
        Acrobat Profile File
        Homesite Project File
  .API  Lotus Printer Driver Info
        Photoshop Ink Colors Setup
        Application Program Interface
  .APL  Centura Team Developer Application Library File
        APL Workspace File
  .APP  R:Base, Symphony, DR-DOS, FoxPro (or other) Application
        Centura Team Developer Normal Mode Application File
  .APR  Lotus Approach 97 File
        ArcView Project File

  .APS  MS Visual C++ File

  .APT  Centura Team Developer Text Mode Application File
        Lotus Approach Data View File
  .APX  Lotus Approach Paradox-specific Information File
        Borland C++ Appexpert Database
  .AQ   Applix Data
  .ARC  Archive File
        Compressed File
  .ARF  Automatic Response File
  .ARI  Aristotle Audio File
        Compressed Archive
  .ARJ  Compressed Archive
  .ARK  Compressed Archive
  .ARL  AOL Organizer File
  .ARR  Atari Cubase Arrangement
  .ART  Clip Art File
        Xara Studio Drawing
        Canon Crayola Art File
        Another Ray Tracer Format
        AOL Johnson-Grace Compressed File
        First Publisher Raster Graphic
  .ARX  Compressed Archive
  .AS   Applix Spreadsheet
  .ASA  MS Visual InterDev File
        Active Server Document
  .ASC  ASCII Text File
        PGP Armored Encrypted File
  .ASD  MS Word Automatic Backup
        Lotus Screen Driver
        MS Advanced Streaming Format Description File  
  .ASE  Velvet Studio Sample
  .ASF  MS Active Streaming (Media) File
        Statgraphics Data
        Lotus Screen Font
        APL*Plus/PC APL Shared File
        Electronic Arts Music File
  .ASH  TASM Assembler Header
  .ASI  Borland Assembler Include
  .ASK  askSam Database
  .ASM  Assembler Source Language (various)
  .ASO  Assembler Object
        Astound Dynamite Objects
  .ASP  Active Server Page
        Procomm Plus ASPECT Program
        Astound Presentation File
        Photoshop Photo File Index
        Photoshop Separation Setup
  .ASR  Ms Automap Route
        Photoshop Scratch Area
  .AST  Astound Multimedia File
        Photoshop Separation Tables
        Claris Works Assistant File
  .ASV  DataCAD Autosave File
        Photoshop Selective Color
  .ASX  MS Windows Media Active Stream Redirector File
        Cheyenne Backup Script
        Video File
  .AT2  Aldus Persuasion 2.0 Auto Template
  .ATF  Photoshop Transfer Function
  .ATM  Adobe Type Manager Data File
  .ATT  AT&T Group 4 Bitmap (fax)
  .ATW  AnyTime Deluxe PIM File
  .AU   Music File (various)  [Viewer]
  .AUD  Audio File used by Westwood Studios for various games
  .AUX  TeX/LaTeX Auxilliary Reference File
        ChiWriter Auxilliary Dictionary File
  .AVA  Avagio Publication
  .AVB  Inculan Anti-Virus Virus Infected File
  .AVI  Audio Video Interleave File  [Viewer]
  .AVR  Audio Visual Research Sound File
  .AVS  Animation File
        Application Visualization System Format
        Stardent AVS-X Image
        Winamp Advanced Visualization Studio File
  .AVX  ArcView File
  .AW   HP AdvanceWrite Text File
        Applix Word File
  .AWD  Faxviewer Document
  .AWK  AWK Script
  .AWM  Animation Works Movie
  .AWR  Telsis Digital Audio File
  .AWS  StatGraphics Data File
  .AXL  ArcIMS XML Project File
  .AXR  Telsis Digital Audio File
  .AXT  ASCII Application Object Template 
        Photoshop Replace Color/Color Range

  .B    Limbo Implementation File (Inferno OS)
  .B1J  BookJones
  .B1N  1st Reader Binary Screen Image
  .B1S  BookSmith
  .B30  Ventura Publisher Printer Font
  .B3D  3D Builder File
  .B4   Helix Nuts and Bolts File (Helix Software now part of McAfee)
  .B64  Base 64 MIME-encoded File
  .B8   Piclab Raw Graphic File

  .BAC  Backup
  .BAD  Rime Mailer Address File
        Oracle BAD File
  .BAK  Backup
  .BAL  Ballade Music Score
  .BAR  dBase Application Generator Horizontal Menu Object
  .BAS  BASIC Language Source
        Basic Module
  .BAT  Batch Processing
  .BB   Papyrus Database Backup
  .BBL  TeX/BibTeX Bibliographic Reference File
  .BBM  Deluxe Paint Image File
  .BBS  Bulletin Board Sytem Text
  .BCH  dBase Application Generator Batch Process Object
        Phoenix Software (Datalex) Entry Point 90 Data File
  .BCK  Backup
  .BCM  MS Works Communications File
  .BCO  Bitstream Fontware File
  .BCP  Borland C++ Makefile
  .BCW  Borland C++ 4.5 Environment Settings
  .BDB  MS Works Dababase File
  .BDF  West Point Bridge Designer File
  .BDF  Egret Data File
  .BDR  MS Publisher Border
  .BEZ  Bitstream Fontware File
  .BF2  Bradford 2 Font
  .BFA  Blowfish-encrypted File (Extension added to original) [Program List]
  .BFC  Briefcase File
  .BFM  UNIX Font Metrics File
  .BFX  BitFax Document
  .BG   MS Backgammon for Windows Game
  .BGA  OS/2 Graphic Array
  .BGI  Borland Graphic Interface
  .BGL  Flight Simulator Scenery File
  .BHF  pcAnywhere Host File
  .BI   Binary File
        Progress Database Before Image File
  .BIB  Bibliography
        TeX/BibTeX Literature Database
  .BIF  GroupWise Initialization File

  .BIG  Chinese (old version)
  .BIK  BioCharter Profile Backup File
  .BIN  Binary File
  .BIO  BioCharter Profile File
        OS/2 Bios File
  .BIT  Bitmap Image  
  .BK   Backup
        JetFax Faxbook File
  .BK!  Backup
  .BK$  Backup
  .BK1  Backup (Can be 1 to 9, usually with WordPerfect)
  .BKI  Backup Index
  .BKP  Backup  
  .BKS  Bookshelf Backup
        IBM BookManager Read Bookshelf
        MS Works Spreadsheet Backup
  .BKW  FontEdit Fontset Mirror Image
  .BLB  DreamWorks Resource Archive 
  .BLD  BASIC Bload Graphics
  .BLK  WordPerfect Temp File
        Alias Wavefront Image
  .BLT  Wordperfect for DOS File
  .BM   Graphic (bitmap)
  .BM1  Apogee BioMenace Data File
  .BMF  Image File  
  .BMI  Buzz Instrument
  .BMK  Help Bookmark
  .BMP  Windows OS/2 Bitmap Graphics  [Viewer]
  .BMS  Backup Magic Backup Set
  .BMW  Buzz Music File with Waves
  .BMX  Buzz Music File
  .BN   AdLib Instrument Bank
  .BNK  Adlib Instrument Bank
        SimCity Game File
        (reported to be) Bink Compressed Video/Audio File

  .BOM  Orcad Schematic Capture Bill of Materials File
  .BOO  Image File
        Compressed Archive File  
  .BOX  Notes Mailbox
  .BPC  Business Plan Toolkit Chart
  .BPL  Delphi Library
  .BPS  MS Works Document
  .BPT  Bitmap Master File
  .BPX  Truevision Targa Bitmap
  .BQY  BrioQuery File
  .BR   Bridge Script
  .BR3  Bryce 3D Scene File
  .BRC  Bryce 2 Scene File
  .BRD  EAGLE Board File
  .BRI  Basic Rate Interface File
  .BRK  Brooktrout Fax-Mail File

  .BRX  Multimedia Browsing Index

  .BS_  MS Bookshelf Find Menu Shell Extension
  .BS1  Apogee Blake Stone Data File
  .BSA  BSARC Compressed Archive
  .BSC  Apple II Compressed Archive

        Boyan Script
        MS Developer Studio Browser File
  .BSK  Bryce 4 File
  .BSP  Quake Map
  .BSV  BASIC Bsave Graphics
  .BTM  4DOS Batch To Memory Batch File
  .BTN  ButtonWare File
  .BTR  Btrieve Database File
        MS Frontpage-related File
  .BUD  Quicken Backup
  .BUG  Bug (Problem) File
  .BUN  CakeWalk Audio Bundle File
  .BUP  Backup
  .BUT  Buttons! Button Definition
  .BUY  Movie Data File
  .BV1  WordPerfect Overflow File (Can be 1 to 9)
  .BW   SGI Black and White Image

  .BWB  Visual Baler Spreadsheet File
  .BWR  Kermit Beware Bug List
  .BWV  Business Wave File
  .BYU  Movie File
  .BZ   Bzip UNIX Compressed File
  .BZ2  Bzip UNIX Compressed File (Replaces .BZ)

  .C    C Program File

  .C00  Ventura Print File
  .C01  Typhoon Wave File
  .C86  C86 C Program 
  .C--  Sphinx C-- Source code
  .CA   Telnet Server Initial Cache Data File
  .CA7  Beta 44 Job File
  .CAB  Cabinet File (Microsoft installation archive)
  .CAC  dBase IV Executable File
  .CAD  Softdesk Drafix CAD File
  .CAG  MS Clip Gallery Catalog File
  .CAL  SuperCalc Worksheet
        Calendar File
        CALS compressed bitmap
  .CAM  Casio Camera Graphic  [Viewer]
  .CAN  Navigator Fax
  .CAP  Ventura Caption
        Telix Session Capture
        Compressed Music File
  .CAR  AtHome Assistant File
  .CAS  Comma-delimited ASCII File
  .CAT  dBase Catalog
        Quicken IntelliCharge Categorization File
  .CB   MS Clean Boot File
  .CBC  CubiCalc Fuzzy Logic System File
  .CBI  IBM Mainframe Column Binary Formatted File
  .CBL  COBOL Program
  .CBM  XLib Compiled Bitmap
  .CBT  Computer Based Training
  .CC   C++ Program File
        Visual dBASE Custom Class File
  .CCA  CC:Mail File
  .CCB  Visual Basic Animated Button Configuration
  .CCC  Chat
        Curtain Call Native Bitmap Graphic
  .CCE  Calendar Creator Plus Data File
  .CCF  OS/2 Multimedia Viewer Configuration File
        Symphony Communications Configuration File
  .CCH  Corel Chart
  .CCL  Intalk Communication Command Language
  .CCM  Lotus CC:Mail Mailbox
  .CCO  CyberChat Data File

  .CCR  Chat Room Shortcut
  .CCT  Macromedia Director Shockwave Cast
  .CDA  CD Audio Track
  .CDB  Turbo C Database
        Clipboard File
        CardScan Database
        PowerDesigner Conceptual Model Backup File  
  .CDC  Chromeleon Driver Configuration Plugin
  .CDD  Chromeleon Device Driver
  .CDF  Comma Delimited Format
        Cyberspace Description Format
        MS Channel Definition Format

  .CDI  Phillips Compact Disk Interactive Format
  .CDK  Atari Calamus Document
  .CDM  PowerDesigner Conceptual Model File  
        Visual dBASE Custom Data Module
  .CDR  Corel Vector Graphic
        Raw Audio-CD Data
  .CDT  Corel Draw Template
  .CDX  Compound Index
        Corel Draw Compressed Drawing
        MS Visual Foxpro Index
        Active Server Document
  .CE   FarSide Computer Calendar File
  .CEG  Continuous Edge Graphic
        Tempra Show Bitmap Graphic
  .CEL  Autodesk Animator Graphic
        CIMFast Event Language File
        Kiss Paper Doll File
  .CER  Certificate File  
  .CEX  The Currency Exchanger Rate File
  .CF   Imake Configurtion File
  .CFB  Comptons Multimedia File
  .CFG  Configuration (various)
  .CFL  Corel Flowchart File
  .CFM  Corel FontMaster
        Cold Fusion Template File
        Visual dBASE Windows Customer Form
  .CFN  Atari Calamus Font Data File
  .CFO  TCU Turbo C Utilities C Form Object
  .CFP  Complete Fax Portable Fax File
  .CGA  Ventura CGA Screen Characters
  .CGI  Common Gateway Interface Script
  .CGM  Computer Graphics Metafile
  .CH   Clipper Header
        OS/2 Configuration File
  .CH3  Harvard Chart (Harvard Graphics taken over by Serif)
  .CH4  Charisma 4.0 Presentation
  .CHA  Adobe Pagemaker Kerning Data
  .CHD  FontChameleon Font Descriptor
  .CHF  pcAnywhere Remote Control File
  .CHI  Chiwriter Document
  .CHJ  Help Composer Project
        WordPerfect Temp File
  .CHL  Chromeleon Channel Raw Data
        Configuration History Log
  .CHM  Compiled HTML Help
  .CHN  Ethnograph Data File
  .CHP  Ventura Publisher Chapter
  .CHR  Character or Font File
  .CHT  Cheat Machine Data File
        ChartViewer dBase Interface File
        Harvard Graphics Vector File (Harvard Graphics taken over by Serif)
  .CIF  Ventura Chapter Information

        Easy CD Creator Image
        pcAnywhere Caller File
        Ventura Converted Image File
        Colombo Ipermedia File
  .CIL  Clip Gallery Download Package
  .CIM  Sim City 200 File

  .CIN  OS/2 Change Control File
  .CIR  SuperMax E-CAD Save-File Command
  .CIT  Intergraph Scanned Image
  .CIX  TCU Turbo C Utilities Database Index
  .CK1  iD/Apogee Commander Keen 1 Data File (.CK1 to .CK6)
  .CKB  Borland C++ Keyboard Mapping File
  .CKP  Ingres Checkpoint File
  .CL   Generic LISP Source Code
  .CL3  Easy CD Creator Layout File
  .CL4  Easy CD Creator Layout File
  .CLA  Java Class File (usually .CLASS but can be shortened)
  .CLG  Disk Catalog Database
  .CLL  Crick Software Clicker File  
  .CLO  Cloe Image
  .CLP  Windows Clipboard/Picture  [Viewer]
        Quattro Pro Clip Art
        Clipper 5 Compiler Script
  .CLR  WinEdit Colorization Word List
        1st Reader Binary Color Screen Image
        PhotStyler Color Defintion
  .CLS  Visual Basic Class Module
        C++ Class Definition
  .CM   Craftman Data File
  .CMA  Applix TM1 Database File (text)
  .CMB  Chromeleon Backup Archive
  .CMD  OS/2, WinNT Command File
        DOS CP/M Command File
        dBase II Program File
        1st Reader External Command Menu
  .CMF  Creative Music File
        Corel Metafile
  .CMG  Chessmaster Saved Game
  .CMK  Card Shop Plus File
  .CML  Cheat Machine Library File (Windows)
  .CMM  CEnvi (ScriptEase:Desktop) Batch File
  .CMP  Leadview Bitmap
        Open Access File
        Address Document
        JPEG Bitmap
        CorelDRAW Postscript Printer Header
        Route 66 Address Document
        MS Word for DOS User Dictionary
  .CMR  MediaPlayer Movie
  .CMU  Carnegie Mellon Univeristy Stereo Raster Image
  .CMV  Corel Move Animation
  .CMX  Corel PhotoPaint Image
        Corel Presentation Exchange Image
        Apple Viewer File

  .CNF  Configuration (various)
  .CNM  Windows Application Menu Options and Setup File
  .CNQ  Compuworks Design Shop File
  .CNT  Help File Contents (and other contents needs)
  .CNV  MS Word Data Conversion File
        WS_FTP Pro Upload Conversion File Data
        WordPerfect Temporary File
  .COB  COBOL Program File
        Caligari Truespace Format
        TrueSpace2 Object
  .COD  Code List
        Compiler Program Code
  .COD  Multiplan Data File
        dBase Template Source File

        FORTRAN Compiled Code

  .COL  Autodesk Color Palette
        Multiplan Spreadsheet
        Lotus Notes Import Column Description File
  .COM  Command (Executable file)
  .CON  Knowledgeware Consolidation File
        Simdir Configuration File
  .CP8  CP8 256 Gray Scale Image
  .CPD  Fax Coversheet
        Corel PrintOffice File
        Complaints Desk Script
  .CPE  Fax Coversheet
  .CPF  Complete Fax File
  .CPH  Corel Print House Image
  .CPI  Code Page Information
        ColorLab Image
  .CPJ  CeQuadrant CD Project
  .CPL  Control Panel Extension
        Corel Color Palette
        Compel Presentation
  .CPO  Corel Print House File
  .CPP  C++ Program
        CA-Cricket Presents Presentation
  .CPR  Corel Presents Presentation
        Knowledge Access Graphics
  .CPS  Antivirus Checksum File
        Central Point PC Tools Backup
        Colored PostScript File
  .CPT  Macintosh Compressed File
        Corel Photo-Paint Image  [Viewer]
        dBase Encrypted Memo
        CA Cricket Presents Template
  .CPX  Control Panel Applet
        CryptaPix Encrypted Image
        Corel Presentation Exchange Compressed Drawing
  .CPY  Copy Books Data File
  .CPZ  COMPOZ Music Text

  .CRD  Cardfile (Windows 3.x Database)
  .CRF  Zortech C++ Cross-Reference File
  .CRH  MS Golf Image File
  .CRL  Certificate Revocation List
  .CRP  dBase Encrypted Database
        Visual dBASE Custom Report
        Corel Presents Run-Time Presentation
  .CRS  WordPerfect 5.1 for Windows File Conversion Resource
  .CRT  Certificate File
        Oracle Terminal Settings Info
        UNIX Crontab File (not a required extension for Crontab)
  .CRU  CRUSH Compressed Archive
  .CRY  Crypto Chat II Encrypted Notebook-content
  .CSA  Comma Deliminated Text
  .CSC  Corel Script
  .CSD  Bitstream Fontware File
        Chemsoft® MSDS Database File

  .CSH  Hamilton Labs C Shell Script File
  .CSI  Cyberautograph Signed Item
  .CSK  Claris Works
  .CSM  Borland C++ Symbol File
        Borland C++ 4.5 Precompiled Header
        Kodak DC265 Camera Script

  .CSP  PC Emcee On-Screen Image
  .CSQ  Foxpro Queries
  .CSS  Hypertext Cascading Style Sheet
        Stats+ Datafile
        Statistica Datasheet
  .CST  Macromedia Director Cast File
  .CSV  Comma-Separated Variables
        CompuShow Adjusted EGA/VGA Palette
  .CT   Scitex CT Bitmap

  .CTF  TIFF Compressed File
        Symphony Character Code Translation
  .CTL  Setup Information (various)
        User Control (various)
  .CTX  Compressed Text
        Visual Basic User Control Binary File
        Pretty Good Privacy (PGP) Ciphertext File
        MS Online Course Text
  .CTY  SimCity City File
  .CUE  MS Cue Cards Data
  .CUF  Turbo C Utilities Form Definition
  .CUL  IconForge/ImageForge Cursor Library
  .CUR  Cursor  [Viewer]
  .CUT  Dr. Halo Bitmap Graphic
  .CV   Corel Versions Archive
        MS CodeView Information
  .CV4  Codeview Colors

  .CVP  WinFax Cover Page
  .CVS  Canvas Drawing File
  .CVT  dBase Converted Database
  .CVW  Codeview Colors
  .CWE  Crossword Express
  .CWK  Claris Works Data
  .CWS  Claris Works Template
  .CXT  Macromedia Director Protected Cast File
  .CXX  Zortech C++ Program
  .CYP  Cypherus Encrypted Archive

  .D    Dialect Source Code File

  .D3D  CorelDream 3D File
  .D64  Commodore 64 Emulator Disk Image
  .D8A  AmBiz Productivity Pak Catalog
  .DAD  Chromeleon Channel Raw Data

  .DAP  Omnis5 Application File
        MS Access Data Access Page
  .DAT  Data (multiple programs)
        WordPerfect Merge Data
        (also possibly) MPEG File
  .DB   Paradox Database
        Progress Database
  .DB2  dBase II File
  .DBC  MS Visual Foxpro Database Container
  .DBF  Database (multiple programs) [started as dBASE]
        Oracle 8.x Tablespace File
  .DBK  dBase Database Backup
        Orcad Schematic Capture Backup File
  .DBM  Cold Fusion Template
  .DBO  dBase IV Compiled Program File
  .DBQ  Paradox Memo
  .DBT  Database Text File [dBASE]
  .DBV  Flexfile Memo Field File
  .DBW  DataBoss Database File
  .DBX  Database (multiple programs)
        DataBeam Image
        MS Visual Foxpro Table
  .DC   DesignCAD CAD File
  .DC2  DesignCAD CAD File
        Kodak DC25 Digital Camera File
  .DC5  DataCAD Drawing File
  .DCA  Visual Basic Active Designer Cache
        IBM DisplayWrite Document Content Architecture Text File
  .DCD  Document Content Description File 
  .DCF  Design Rule for Camera File Systems File

  .DCM  DCM Module Format
  .DCP  Delphi Compiled Packages
        OS/2 Data CodePage
  .DCR  Shockwave File
  .DCS  Quark Desktop Color Separation Specification
        ACT! Activity Data File
  .DCT  Dictionary (various)
        MS Visual Foxpro Database Container
  .DCU  Delphi Compiled Unit
  .DCX  FAX Image  [Viewer]
        Bitmap Graphics  [Viewer]  
        MS Visual Foxpro Database Container
  .DD   Macintosh Compressed Disk Doubler Archive
  .DDB  Bitmap Graphics File
  .DDE  Dynamic Data Exchange
  .DDF  BTRIEVE Database
        Bitstream Fontware File
  .DDI  DiskDupe Image
        Disk Doubler Image
  .DDP  OS/2 Device Driver Profile File
  .DEB  DOS Debug Script
        Debian Linux Package
  .DEF  Definitions
        SGML Tag Definition
        SmartWare II Data File
        C++ Definition

        Geoworks Assembly Header File

  .DEL  Data
  .DEM  Descent Demonstration
        USGS Map  
  .DEP  Setup Wizard Dependency  
  .DER  Certificate File
  .DES  Description Text
  .DEV  Device Driver
        Device Independent TeX
        LaTeX File
  .DEZ  DES Encrypted Zip File
  .DF1  Omnis7 and Omnis Studio Database File (also .DF2, .DF3, etc.)
  .DFD  File Flow Diagram Graphic
  .DFI  Digifont Outline Font Description
  .DFL  Signature Default Program Settings
  .DFM  Delphi Forms
        File Flow Diagram Model  
  .DFS  Delight Sound File
  .DFV  Word Print Format Template
  .DG   Autotrol Graphics
  .DGC  TurboTax-related File
  .DGN  Microstation95 CAD Drawing File
        Intergraph Graphics
  .DGS  AT Advanced Diagnostics File
  .DH   Geoworks Dependency Information File
  .DHP  Dr. Halo PIC
  .DHT  Gauss Data File
  .DIA  Computer Support Corp Diagraph Graphics File
  .DIB  Device-Independent Bitmap Graphic  [Viewer]
  .DIC  Dictionary (various)
  .DIF  Data Interchange Format
  .DIG  Text Document
        Digilink Format
        Sound Designer Audio File
  .DIP  Graphics File
  .DIR  Procomm Plus Dialing Directory
        Macromedia Director File
        DEC VAX Directory

  .DIS  Corel Draw Thesaurus
  .DIT  MS Win2000 Active Directory Schema
  .DIZ  Description In Zip File
  .DKB  DKBTrace Ray-Traced Graphics File
  .DL   Animations file
  .DLD  Lotus File
  .DLG  Dialog Resource Script
        C++ Dialogue Script
  .DLL  Dynamic Link Library
        CorelDraw Export/Import Filter
  .DLS  Downloadable Sounds (Interactive Music Architecture)
        Norton DiskLock Setup File
  .DMD  Visual dBASE Data Module
  .DMF  Delusion/XTracker Digital Music File
        Packed Amiga Disk Image
  .DMO  Demo  
  .DMP  Dump (various)
  .DMS  Compressed Archive  
  .DNE  Darn v5+ (Windows) Events List
  .DOB  User Document Form File  
  .DOC  Document or Documentation (many programs/formats)
        MS Word Document
  .DOG  Laughing Dog Screen Saver
  .DOH  Geoworks Dependency Information File

  .DOS  Text File/DOS Specification Info
  .DOT  MS Word Document Template
        Corel Lines-Definition
  .DOX  Text File
        MultiMate Document
        User Document Binary Form File  
  .DOZ  VENDINFO Description Out of Zip File
  .DP   Daily Planner Calendar File
        DataPhile Data File
  .DPA  Serif DrawPlus Animation
  .DPJ  DeskProto CAM Project File
  .DPK  Delphi Package File
  .DPL  Borland Delphi 3 Packed Library
  .DPP  Serif DrawPlus Drawing
  .DPR  Borland C++ (or Delphi) Default Project
  .DPT  Publish-It! Publication File
  .DPX  Digital Moving Picture Exchange
  .DQY  MS Excel ODBC Query File

  .DRC  Orcad Schematic Capture Design Rules Check Report File
  .DRN  Darn for DOS
  .DRS  WordPerfect Driver Resource
  .DRV  Device Driver
  .DRW  Drawing (various)
        Micrografx Vector Graphic
        Pro/E Drawing
  .DS4  Micrografx Designer Graphics (ver 4)
  .DSC  Oracle Discard File
        Nikon Coolpix Disk Identification File
  .DSD  DataShaper Database File
        Document Structure Definition File 
  .DSF  Micrografx Designer
        Delusion/XTracker Digital Sample
  .DSG  Doom Saved Game
  .DSK  Borland C++ or Turbo Pascal Project Desktop File
        Novell Driver File
  .DSL  Lingvo User Feature Dictionary
  .DSM  Delphi Symbol File
        Digital Sound Module Tracker Format
        Dynamic Studio Music Module

  .DSN  ODBC Data Source
        SureThing Office Labeler (formerly DesignExpress) Document

        Orcad Schematic Capture Schematic File
  .DSP  Signature Display Parameters
        Dr. Halo Graphic Screen Driver
        MS Developer Studio Project
  .DSQ  Corel QUERY File
  .DSR  WordPerfect Driver
        Active Designer File  

  .DSS  Digital Soup Digital Sound File

  .DST  Embroidery Machines Graphics File
  .DSW  MS Developer Studio Workspace
        Borland C++ Desktop Settings
  .DSX  Active Designer Binary File  
  .DT_  Macintosh Data File Fork
  .DTA  Data (Various)
  .DTD  SGML Document Definition File
  .DTF  Q&A Database  
  .DTM  DigiTrekker Module
  .DTP  SecurDesk! Desktop
        Timeworks Publisher Text Document
        Pressworks Template File
  .DUN  Dial-Up Network
  .DUP  Duplicate Backup
  .DV   DESQview Script
        Digital Video File
  .DVC  Lotus File
  .DVF  DV Studio Camcorder Graphics File
  .DVI  Device Independent Document  
  .DVP  DESQview Program Information
        AutoCAD Device Parameter
  .DVR  Device Driver
  .DW2  DesignCAD Drawing File
  .DWC  Compressed Archive
  .DWD  DiamondWare Digitized File
  .DWF  Autodesk Vector Graphic

  .DWG  AutoCAD Drawing Database
  .DWP  Dweep Game Levels
        DeScribe Document File
  .DWS  Dyadic Workspace File
  .DWT  AutoCAD Template/Prototype File
  .DX   Document Imaging File
        Digital Electric Corporation (DEC) Data Exchange File
  .DXB  Drawing Interchange Binary
  .DXF  AutoCAD Drawing Interchange Format
  .DXN  Fujitsu dexNet Fax Document
  .DXR  Macromedia Director Protected Movie File
  .DYN  Lotus File

  .EBJ  Geoworks Error Checking Object File
  .ECC  Ecchi Role-playing Format (Generally X-rated Anime File)
  .ECW  Ensoniq Waveset Format
  .ED   EasyDraw CAD File (Japanese CAD program)
  .ED5  EDMICS Graphics File
  .ED6  EDMICS Graphics File
  .EDA  Ensoniq ASR Disk Image
  .EDB  ROOTS3 Geneological Data
  .EDD  FrameMaker Element Definition Document
  .EDE  Ensoniq EPS Disk Image
  .EDK  Ensoniq KT Disk Image
  .EDQ  Ensoniq SQ1/SQ2/KS32 Disk Image
  .EDS  Ensoniq SQ80 Disk Image
  .EDT  VAX Edt Default Settings
  .EDV  Ensoniq VFX-SD Disk Image
  .EEB  WordPerfect Equation Editor Button Bar
  .EFA  Ensoniq ASR File
  .EFE  Ensoniq EPS File
  .EFK  Ensoniq KT File
  .EFQ  Ensoniq SQ1/SQ2/KS32 File
  .EFS  Ensoniq SQ80 File
  .EFT  Chiwriter High Res Screen Characters
  .EFV  Ensoniq VFX-SD File
  .EFX  Everex EFax Fax Document
  .EGA  Ventura EGA Screen Characters

  .EL   eMacs Lisp Source Code
  .ELC  eMacs Lisp Byte-compiled Source Code
  .ELF  Black Belt Systems Extended Layer File
  .ELI  Encyclopedia Article List
  .ELM  MS FrontPage Theme-Pack File
  .ELT  Event List Text  
  .EMB  Everest Embedded Bank File
  .EMD  ABT Extended Module
  .EMF  Extended Windows Metafile Format  [Viewer]
  .EML  MS Outlook Express Electronic Mail
  .EMS  PC Tools Enhanced Menu System Config
  .EMU  Emulation  
  .ENC  UUENCODEd Encoded File
        Video File
        Knowledgeware Encyclopedia
        Encore Music File
  .END  Corel Arrow Definition
  .ENG  Dictionary

  .ENR  Enroute Toolath
  .ENV  WordPerfect Environment

  .EPD  Express Publisher Publication File
  .EPI  Express Publisher Document File
  .EPS  Encapsulated PostScript  [Viewer]
        Ventura Printer Font
  .EQN  WordPerfect Equation
  .ER1  ERWin File
  .ERD  Entity Relationship Diagram  
  .ERM  Entity Relationship Diagram Model
  .ERR  Error Log (various)
  .ERX  ERWin File
  .ESF  Emblaze Audio File
  .ESH  Extended Shell Batch File
  .ESI  Esri Plot File
  .ESL  MS Visual FoxPro Distributable Support Library
  .ESP  Ventura File

  .EST  MS Streets & Trips 2001 Trip File
  .ETH  Ethnograph Document File
  .ETX  SetText Structure Enhanced Text
  .EUC  Japanese (Kanji)
  .EUI  Ensoniq EPS Family Compacted Disk Image
  .EVT  PC Tools Event File Scheduler
        MS WinNT/2000 Event Log
  .EVY  Envoy Document
  .EWD  Express Publisher for Windows Document
  .EWL  MS Encarta Document
  .EX3  Harvard Device Driver (Harvard Graphics taken over by Serif)
  .EXC  QEMM Exclude File
        REXX Program
        MS Word Exclusion Dictionary
        Text Document
  .EXE  Executable File
  .EXP  ICQ Saved Chat File
  .EXT  Norton Commander Extension File

  .EYB  Encyclopedia Yearbook File
  .EZP  Edify Electronic Workforce Backup Utility
  .EZS  Sunburst Technology Easy Sheet Document
  .EZT  Sunburst Technology Easy Sheet Template

  .F    Compressed Archive File (UNIX)
        FORTRAN Program
  .F01  Perfect Fax Document
  .F06  DOS 6 Pixel Screen Font
  .F07  DOS 7 Pixel Screen Font
  .F08  DOS 8 Pixel Screen Font
  .F09  DOS 9 pixel Screen Font
  .F10  DOS 10 Pixel Screen Font
  .F11  DOS 11 Pixel Screen Font
  .F12  DOS 12 Pixel Screen Font
  .F13  DOS 13 Pixel Screen Font
  .F14  DOS 14 Pixel Screen Font
  .F15  DOS 15 Pixel Screen Font
  .F16  DOS 16 Pixel Screen Font
  .F2R  Farandoyle Linear Module Format
  .F3R  Farandoyle Blocked Module Format
  .F32  Raw 32-bit IEEE Floating Point Values
  .F64  Raw 64-bit IEEE Floating Point Values
  .F77  FORTRAN 77 Program
  .F90  FORTRAN Program
  .F96  Frecom FAX96 Document
  .FAC  FACE Graphic
  .FAQ  Frequently Asked Questions
  .FAR  Farandoyle Tracker Music Module
  .FAS  3D Fassade Plus Basic Module
  .FAV  MS Outlook Bar Shortcuts
  .FAX  Fax File
  .FBC  FamilyTree Compressed Backup File
  .FBK  Navison Financials Backup
        FamilyTree Backup File
  .FBM  Fuzzy Bitmap
  .FBS  File Burner Skin
  .FC   Harvard Dictionary (Harvard Graphics taken over by Serif)
  .FCD  Virtual CD-ROM
        FastCAD/EasyCAD Output
        Patton & Patton Flow Charting 3 File

  .FCT  Foxpro Catalog
  .FD   FORTRAN Declarations
        Dataflex Field Compiler Offsets
  .FDB  Navison Financials Database
        Art Explosion Portfolio Catalog File
  .FDF  Adobe Acrobat Forms Document

  .FDX  Force Index
  .FEB  WordPerfect Figure Editor Button Bar
  .FEM  CADRE Finite Element Mesh File
  .FEX  Focus File
  .FF   AGFA CompuGraphics Outline Font Description
  .FFA  MS Fast Find File
  .FFF  GUS PnP Bank
        defFax Fax Document
  .FFL  MS Fast Find File
        PrintMaster Gold Image File
  .FFO  MS Fast Find File
  .FFT  DCA/FFT Final Form Text
  .FFX  MS Fast Find File
  .FGA  Folder Guard Attributes
  .FGD  Folder Guard Data
  .FGP  Folder Guard Passwords File
  .FH3  Aldus Freehand 3 Drawing
  .FH4  Aldus Freehand 4 Drawing
  .FI   FORTRAN Interface File
  .FIF  Fractal Image Format
  .FIG  REND386/AVRIL Graphic
  .FIL  dBase Files List Object
        WordPerfect Overlay

  .FIN  WordPerfect Print Format Text

  .FIT  FITS Graphic

  .FIX  Generic Patch File
  .FKY  Foxpro Macro
  .FLA  Macromedia Flash Movie
  .FLB  Papyrus Format Library
  .FLC  AutoDesk FLIC Animated Picture
  .FLD  Charisma Folder
        Hijaak Thumbnail Folder

  .FLF  Corel Paradox Form
        OS/2 Driver File
        Navison Financials License File
  .FLI  Autodesk FLIC Animation

  .FLL  Foxpro Library
  .FLM  AutoCAD Film
  .FLO  MicroGrafx FlowCharter File
  .FLR  Live3D File

  .FLT  Corel Graphic Filter
        StarTrekker Music Module
        MulitGen Open Flight File
        Asymetrix Graphics Filter Support File
        Micrografx Picture Publisher Filter

  .FLX  Image File
        Dataflex Ordered Binder
        DataFlex Compiled Binary File
  .FM   Adobe FrameMaker Document
        FileMaker Pro Spreadsheet
  .FM1  Lotus Spreadsheet File
  .FM3  Harvard Device Driver (Harvard Graphics taken over by Serif)
        1-2-3 Format File
  .FMB  WordPerfect File Manager Button Bar
        Oracle Binary Form Source Code
  .FMD  Open Access File

  .FML  GetRight File Mirror List
        Oracle Mirror List
  .FMO  dBase Ordered Format
  .FMP  FileMaker Pro Document
  .FMT  Format File
        Style Sheet  
        Oracle Text Form Format
        MS Schedule+ Print File
        MS Visual FoxPro Csreen Format File
  .FMV  Frame Vector Metafile
  .FMX  Oracle Executable Form
  .FN3  Harvard Graphics Font
  .FND  MS Explorer Saved Search
  .FNG  Font Navigator Group File
  .FNK  FunkTracker Module
  .FNO  Folio Infobase
  .FNT  Font File
  .FO1  Borland Turbo C Font
  .FO2  Borland Turbo C Font
  .FOG  Fontographer Font
  .FOL  1st Reader Saved Message Folder
  .FON  Font File
        Procomm Plus Call Log
  .FOR  FORTRAN Source
        WindowBase Form
  .FOT  Installed TrueType Font
  .FOX  FoxBase File
  .FP   FileMaker Pro File
  .FP1  Flying Pigs for Windows Data
  .FP3  FileMaker Pro File
  .FP5  FileMaker Pro Document
  .FPC  FoxPro Catalog File
  .FPT  FileMaker Pro File
        FoxPro Memo Fields
  .FPW  FloorPlan Plus Floorplan Drawing
  .FPX  FlashPix Bitmap  [Viewer]
  .FR3  dBase IV Renamed dBaseIII+ Form
  .FRF  FontMonger Font
  .FRG  dBase IV Uncompiled Report
  .FRM  Form File
        FrameMaker Document
        FrameBuilder Document
        Oracle Executable Form
        Visual Basic Form
        WordPerfect Merge Form
        DataCAD Symbol Report File
  .FRO  dBase IV Compiled Report
        FormFlow File
  .FRP  PerForm Pro Plus Form
  .FRS  WordPerfect Graphics Driver
  .FRT  FoxPro Report File
  .FRX  Visual Basic Binary Form File
        FoxPro Report File
  .FRZ  FormFlow File
  .FSF  Convert It! Factor File
        fPrint Audit Tool File
  .FSL  Borland's Paradox 7 Forms
        Corel Paradox Saved Form
  .FSM  Farandoyle Sample Format
  .FSS  Iomega Backup File Selection Set
  .FST  FastStats Analyzer File
        dbFast Linkable Program
  .FSX  Lotus 1-2-3 Data
  .FT   Lotus Notes Full Text Index
  .FTB  Roots3 Index File
  .FTG  Windows Help Full-text Search Group File
  .FTM  Family File
        MicroGrafx Font
  .FTS  Windows Help Full-Text Search Index File
  .FTV  Forest & Trees File
  .FTW  Family File
  .FW   Framework Database
  .FW2  Framework II File
  .FW3  Framework III File
  .FW4  Framework IV File
  .FWB  FileWrangler Data File Backup
  .FWL  FileWrangler EXE Library
  .FWS  FileWrangler Data File for File Splitting Configuration
  .FX   FastLynx On-Line Guide
  .FXD  WinFax Sent Document
        FAXit Phonebook
  .FXI  File-Ex File
  .FXP  FoxPro Compiled Source
  .FXR  WinFax Received Document
  .FXS  WinFax Fax Transmit Graphic
  .FZB  Casio FZ-1 Bank Dump
  .FZF  Casio FZ-1 Full Dump
  .FZV  Casio FZ-1 Voice Dump

  .G3   G3 FAX File  [Viewer]
  .G3F  Zetafax TIFF File (fine resolution)
  .G3N  Zetafax TIFF File (normal resolution)
  .G4   GTX RasterCAD File
  .GAL  Gallery of Pictures
        Corel Multimedia Manager Album
  .GAM  GammaFax Fax Document
  .GB   Chinese
        Nintendo GameBoy Emulator ROM Image File
  .GBC  Nintendo GameBoy Color Emulator ROM Image File
  .GBK  Interbase Database Backup
  .GC   Sierra Print Artist File
  .GC1  Golden Common Lisp Source Code
  .GC3  Golden Common Lisp Source Code
  .GCA  GOCA Graphics File
  .GCD  Generic CADD Drawing
  .GCF  WinXComp Grouped Compressed File
  .GCI  GTA2 Game File
  .GCP  Ground Control Point File (map projection)
  .GDB  Interbase Database
  .GDM  Bells, Whistles, and Sound Boards Module
  .GDS  Image File
  .GED  GEDCOM Family History File
        Graphic Environment Document
        Arts & Letters Graphics File
  .GEM  GEM (a desktop interface) File
        Ventura Publisher Vector Graphics
  .GEN  Ventura-Generated Text File
        Chromeleon Generic Driver Configuration
        dBase Application Generator Compiled Template
  .GEO  VideoScope File
  .GFC  Patton & Patton Flowcharting 4 File
  .GFI  Genigraphics Graphics Link Presentation
  .GFT  NeoPaint Font
  .GFX  Genigraphics Graphics Link Presentation
  .GHO  Symantec Ghost Disk Image File
  .GID  Windows Help Index File
  .GIF  Graphic Interchange Format  [Viewer]
  .GIM  Genigraphics Graphics Link Presentation
  .GIX  Genigraphics Graphics Link Presentation
  .GKH  Ensoniq EPS Family Disk Image
  .GKS  Gravis GripKey Document
  .GL   Animated Picture
  .GLY  MS Word Glossary
  .GMP  GTA2 Game File
  .GNA  Genigraphics Graphics Link Presentation
  .GNT  Micro Focus Generated Code
  .GNX  Genigraphics Graphics Link Presentation
  .GP3  CCITT Group 3 File (fax)
  .GP4  CCITT Group 4 File (fax)
  .GPH  Lotus 1-2-3 Graph
  .GPP  Serif GraphicsPlus Object
  .GR2  Windows 3.0 Screen Driver
  .GR3  Windows 3.0 Screen Grabber
  .GRA  Flight Simulator File
        MS Graph Chart
        SigmaPlot Data File
  .GRB  MS-DOS Shell Monitor
  .GRD  Gradebook Power File
        Map Projection Grid File
  .GRF  Graph
        Golden Software Graph File
        Grafix Idea File
  .GRP  Program Manager Group
  .GRY  Picture File
  .GSM  Raw GSM 6.10 Audio Stream
        US Robotics Modem File
  .GSP  Geometer's Sketchpad Material File
  .GT2  Graoumftracker Music Module (new)
  .GTK  Graoumftracker Music Module (old)
  .GTY  Gibson Tray File
  .GWP  Greetings WorkShop File  [Now MS Picture It!]
  .GWX  Genigraphics Graphics Link Presentation
  .GWZ  Genigraphics Graphics Link Presentation
  .GX1  Show Partner Graphics File
  .GX2  Show Partner Graphics File
  .GXL  Genus Graphics Library
  .GXT  GTA2 Game File
  .GZ   Gzip Compressed Archive

  .H    Header (Usually C Compiler)
  .H!   Flambeaux Tutorial Database
  .H++  C++ Header File
  .H--  Sphinx C-- Header File
  .HA   Compressed Archive
  .HAM  Image File
  .HBK  Mathcad Handbook
  .HDF  Hierarchical Data Format File
  .HDL  Procomm Plus Alternate Download File Listing
  .HDR  Procomm Plus Message Header
        PC-File+ Database Header
  .HDX  Help Index (Various)
  .HED  HighEdit Document
  .HEL  MS Hellbender Saved Game
  .HEX  Hex Dump
        Macintosh BinHex 2.0 File
  .HFI  HP Font Info
  .HFX  HotFax File
  .HGL  HP Graphics Language
  .HH   C++ Header
        Help Topic Map File
  .HHC  Table of Contents File (HHW Application)
        TurboTax Contents File
  .HHH  Power C Precompiled Header
  .HHK  Help Workshop Index File
  .HHP  Procomm Plus Help Data
  .HHP  HTML Help Project
  .HLP  Windows Help File
  .HMI  Descent Human Machine Interfaces MIDI File
  .HMM  Procomm Plus Alternate Mail Read Option Menu
  .HMP  Descent Human Machine Interfaces MIDI File
  .HOF  Hall Of Fame (scores)
  .HOG  Lucas Arts Dark Forces WAD File
        Descent Mission File
  .HPF  PageMaker HP LaserJet Fonts
  .HPG  Hewlett-Packard Graphics (plotter)
  .HPI  Gem Font Information
  .HPJ  Help Project File
  .HPK  Compressed Archive  
  .HPL  HP Graphics File
  .HPM  Procomm Plus Alternative Menu
  .HPP  C++ Program Header
  .HPR  RoboHELP Configuration File
  .HQX  Binhex Text Conversion File (Macintosh)
  .HRL  Herolab EasyWin32
  .HPM  Procomm Plus Alternate Main Menu
  .HPP  Zortech C++ Header
  .HPR  RoboHelp Configuration
  .HQX  Macintosh BinHex 4 Compressed Archive
  .HRM  Procomm Plus Alternate Main Menu
  .HRX  Herolab EasyWin32
  .HRZ  Image File
  .HSQ  Data File Associated with Qaz Trojan
  .HSS  Photoshop Hue/Saturation Information
  .HST  History File
        Procomm Plus History File
        Host File
  .HT   HyperTerminal
  .HTA  Hypertext Application (run apps from HTML doc)
  .HTF  WebBase File
  .HTI  WebBase File
  .HTM  Hypertext Markup Language
  .HTT  Hypertext Template
  .HTX  Extenended Hypertext Template
        Internet Database Connector File
  .HWP  Hangul (Korean) Word Processor File 
  .HXM  Procomm Plus Alternate Protocol Selection Menu
        Descent2 HAM File
  .HXX  C++ Header
  .HY1  Ventura Publisher Hyphenation Algorythm
  .HY2  Ventura Publisher Hyphenation Algorythm
  .HYC  WordPerfect Hyphenation File
  .HYD  WordPerfect Hyphenation Dictionary
  .HYP  Hypertext File
        Hyphenation File
        Compressed Archive  
  .HZ   Chinese

  .I    Progress Include File
  .IBA  MDE InfoHandler Infobase File
  .IBM  Image File
  .ICA  Citrix File
        IOCA Graphics File
  .ICB  Targa Bitmap
  .ICC  Kodak Printer Image
  .ICE  Archive File
  .ICL  Icon Library File (various) ImageForge/IconForge  [Viewer]
  .ICM  Image Color Matching Profile File
  .ICN  Icon Program
  .ICO  Icon  [Viewer]
  .ICS  Outlook Calendar File
  .ID   Disk Identification File
  .IDB  MS Developer Intermediate File
  .IDD  MIDI Instrument Definition
  .IDE  Integrated Development Environment Configuration File
  .IDF  MIDI Instruments Drivers File
  .IDQ  Internet Data Query File
  .IDX  Index (multiple programs)
  .IEF  Image File
  .IFF  Graphic, Sound (Interchangeable File Format)  [Viewer]
  .IFS  OS/2 System File
        IconForge Image EXE Library
  .IGF  Inset Systems Metafile
  .IGS  IGES-Format
  .IIF  QuickBooks for Windows Interchange File
  .III  Intel Phone Compatible
  .IL   Icon Library
  .IM8  Sun Raster Graphic
  .IMA  WinImage File
  .IMF  ImageForge/ImageForge Image EXE Library
  .IMG  Bitmap Graphic (several programs)  [Viewer]
  .IMP  Urban Chaos Game File
        Lotus Improv Spreadsheet
  .IN3  Harvard Input Device Driver (Harvard Graphics taken over by Serif)
  .INC  Include File (various)
  .IND  dBase IV or DataPerfect Index
  .INF  Information or Setup File
  .INI  Initialization file (many)
  .INK  Pantone Reference File
  .INL  MS Visual C++ Inline Function File
  .INP  Oracle Source Code
  .INS  Internet Communication Setting
        WordPerfect File
        Ensoniq EPS Family Instrument
        Sample Cell / II Instrument
        InstallShield Script
        X-Internet Sign-up File
  .INT  Borland Interface Units
        Foxpro Code Page
        Intermediate Code used for syntax checking (various)
  .INX  Foxbase Index
  .IO   Compressed Archive  
  .IOB  Imagine File
  .IOF  Findit Document
  .ION  Text Program/Installation Description
  .IPL  Corel Pantone Spot Reference Palette
  .IPX  Interactive Pictures Corporation AV File
  .IQY  Excel Web Query
  .IRS  WordPerfect Resource File
  .ISD  RapidFile Dictionary
  .ISH  Compressed Archive File
  .ISO  File List for CD-ROM
  .ISP  X-Internet Sign-up File
        Internet Communication Settings
  .ISS  InstallShield Response File
  .IST  Digitrakker Instrument File (by n-FaCToR)
  .ISU  InstallShield Uninstall Script
        Netscape File
  .IT   Impulse Tracker Music Module
  .ITI  Impulse Tracker Instrument
  .ITS  Internet Document Set
        Impulse Tracker Sample
  .IV   VRML File
        Open Inventor File
  .IVF  Indeo Video File
  .IW   Iconware Application
        Idlewild Screensaver
  .IWA  IBM Writing Assistant Text
  .IWP  Wang Text File
  .IX   Framemaker Index File

  .J62  Ricoh Camera File
  .JAR  Java Archive File  
  .JAS  Compressed Graphic
  .JBC  Jam Byte-Code Hex File (8051 Microprocessor File)
  .JBD  SigmaScan Data File
  .JBF  Paint Shop Pro Browser File
  .JBX  Project Scheduler File
  .JFF  JPEG Image
  .JFI  Image File
  .JIF  JPEG Image
  .JIS  Japanese
  .JMP  SAS JMPDiscovery Chart-to-statistics File
  .JMS  Voxtron TeleButler Graphical Voice Response Call Flow
  .JN1  Epic MegaGames Jill of the Jungle Data File
  .JNB  Sigma Plot Workbook File
  .JNK  Junk (temporary file)
  .JNL  Ingres Journal File
  .JOB  Job File
        Task Scheduler Task Object
        QuestVision Vector Graphics File (IMG File Conversion)
  .JOR  MS SQL Server Journal File

  .JPC  Picture File (Japanese)
  .JPE  JPEG Image
  .JPG  JPEG Image  [Viewer]
  .JS   JavaScript Source Code
  .JSD  eFAX Jet Suite Document
  .JSL  PaintShop Pro File
  .JSP  Java Server Page
  .JT   JT Fax  
  .JTF  JPEG Tagged Interchange Format Image
  .JTK  Sun Java ToolKit File
  .JTP  JetForm File
  .JW   Justwrite Text
  .JWL  Justwrite Text File Library
  .JZZ  Jazz Spreadsheet

  .K25  Kurzweil 2500 Sample
        Kodak DC25 Digital Camera File
  .KAR  Karaoke MIDI File
  .KB   Borland C++ Keyboard Script
        Knowledge Pro Source Code
  .KBD  Keyboard Script File Layout (various)  
  .KBI  Keirsey-Bates Temperament Sorter Index
  .KBM  Reflection Keyboard Script File Layout
  .KBP  Keirsey-Bates Temperament Sorter Profile
  .KBR  Keirsey-Bates Temperament Sorter Data
  .KCL  Kyoto Common LISP Source Code
  .KDC  Kodak Photo-Enhancer  [Viewer]
  .KEX  KEDIT Profile File
  .KEY  Keyboard Macros
        Forecast Pro Datafile
        Program Security or Registration File (various)
        DataCAD Icon Toolbar File
  .KFX  KoFax Group 4 Image
  .KIZ  Kodak Digital Postcard File
  .KKW  RoboHELP Keyword Help project Index File
  .KMP  Korg Trinity KeyMaP File
  .KNO  Personal Knowbase File
  .KPP  SmartPad Toolpad

  .KQP  Konica Camera File
  .KR1  Kurzweil 2000 Sample (multi-floppy)
  .KRZ  Kurzweil 2000 Sample
  .KSC  Korg Trinity Script
  .KSE  Keepsake Studio Export File
  .KSF  Korg Trinity Sample
  .KSH  Prodigy Internet Registration File
  .KTT  KeyText Data File
  .KYB  Keyboard Layout
  .KYE  Kye Game Data

  .L    LEX Program File
        Link Instructions
        LISP Program File
  .LAB  Mailing Labels
  .LAT  Crossword Express Lattice File
  .LAY  Applause Word Chart Layout
  .LBG  dBase IV Label Generator
  .LBL  Labels (various)
  .LBM  Deluxe Paint Bitmap Graphic  [Viewer]
  .LBO  dBase IV Ordered Labels
  .LBR  Compressed Archive File
        Lotus 1-2-3 Display Driver
        Omnis7 Application File
  .LBS	Omnis Studio Application File
  .LBT  Foxpro Label Memo
  .LBX  Foxpro Label
  .LCF  Linker Control File  
  .LCK  MS Frontpage-related File
        Adobe Pagemaker Database File
  .LCN  WordPerfect Dictionary File
  .LD   Telix Long Distance Codes
  .LD1  dBase Overlay File
  .LDB  MS Access Lock File
        TrueVector Log Database
  .LDF  LuraDocument File  [Viewer]
  .LDL  Corel Paradox Delivered Library
  .LEG  Legacy Graphic Format
  .LES  Learn Lesson File
        Logitech Entertainment Game Profile
  .LET  Letter
  .LEX  Lexicon (dictionary file)
  .LFT  Chiwriter Laser Printer Font
        3D Studio Loft File
  .LGC  Program Use Log File (for Windows Program Use Optimization)
  .LGO  MS Windows Logo Driver
  .LGT  Urban Chaos Game File
  .LHA  Compressed Archive File (LZH)
  .LHS  Literate Haskell Source File
  .LHW  Compressed Amiga Archive File  
  .LHZ  LHA Compressed Archive File
  .LIB  Program Library (diverse programmers' languages)
  .LIC  License File (various Shareware)
  .LIF  Compressed Archive File
        HP Logical Interchange Format File
  .LIN  AutoCAD Line Art
  .LIS  Program Listing
        Structured Query Reporting (SQR) Output
  .LIT  MS Reader EBook File
  .LJ   Text File for HP LJ II Printer
  .LKO  MS Outlook Express Linked Object
  .LL3  LapLink III Document File
  .LLC  LapLink Saved Connection File
  .LLX  Laplink Exchange Agent
  .LM8  Picture File
  .LMD  Tune Smithy List of Modes for a Musical Scale
  .LND  3D Landscape Data
  .LNK  Linker File
        Windows Shortcut File
  .LOG  Log File (many different programs)
  .LOK  FileWrangler/ZipWrangler/SecurDesk! Encrypted Archive
  .LP   LP88 Linear Programming for the IBM-PC File
  .LPB  LP88 Linear Programming for the IBM-PC File
  .LPD  Helix Nuts and Bolts File (Helix Software now part of McAfee)
  .LRC  Intel Video Phone File
  .LRF  Linker Response File
  .LRS  WordPerfect Language Resource File
  .LSC  Tune Smithy List of Muscial Scales
  .LSF  Streaming Audio/Video File
  .LSL  Corel Paradox Saved Library
        Lotus Script Library
  .LSP  LISP Program File
  .LST  Listing or List (e.g., packing list)
        PowerPoint File
        Ingres Dump List File
        Oracle Spool File
  .LSX  Streaming Audio/Video Shortcut
  .LTM  Lotus Form
  .LTR  Letter
  .LU   ThoughtWing Library Unit File
  .LVL  Parallax Miner Descent/D2 Level Extension
  .LWF  LuraWave-compressed Graphic File  [Viewer]
  .LWP  Lotus Wordpro 96/97 File
  .LWV  MS Linguistically Enhanced Sound File
  .LYR  DataCAD Layer File
  .LYT  TurboTax Log File
  .LZH  Compressed Archive File
  .LZS  Compressed Archive File  
        Skyroads Data File
  .LZW  Compressed Amiga Archive File  
  .LZX  Compressed File

  .M    Matlab Function
        Macro Source
        Mathematica File
  .M    Limbo Interface Declaration (Inferno OS)
  .M??  Ingres Modify Table/Index File (?? = Hex 00 to FF)
  .M18  Accolade Golf Course File
  .M1V  MPEG File
  .M3   ModuleA 3 Program File
  .M3A  MPEG Archive Enhanced .M3U Playlist File
  .M3D  3D Animations Macro
        Corel Motion 3D Animation
  .MA3  Harvard Macro (Harvard Graphics taken over by Serif)
  .MAC  MacPaint Bitmap Graphic
        Macro (various)
  .MAD  MS Access Module Shortcut
  .MAF  MS Access Form Shortcut
  .MAG  Picture File
        MS Access Diagram Shortcut
  .MAI  Mail
  .MAK  Make File (compiler project file)
  .MAM  MS Access Macro Shortcut
  .MAN  Manual
  .MAP  Image
        Color Palette
        Duke Nukem WAD File
        Ingres Termcap Mapping File
        Linker Map
        Micrografx Picture Publisher Format Data
  .MAQ  MS Access Query Shortcut
  .MAR  MS Access Report Shortcut
  .MAS  Focus Master Data Definition
        MS Access Stored Procedures
        Lotus Freelance Graphics Smartmaster File
  .MAT  Sound File
        Matlab Variables Binary File
        MS Access Table Shortcut
        Autodesk 3D Studio Max and Viz File
  .MAV  MS Access View Shortcut
  .MAW  MS Access Data Access Page
  .MAX  Kinetix's 3D Studio MAX Scene
        Paperport File
        OrCAD Layout File
  .MAZ  Hover Maze Data
        Division's dVS/dVISE File
  .MB   Paradox Memo Holder
  .MB1  Apogee Monster Bash Data File
  .MBF  MS Money Backup File
  .MBK  dBase IV Multiple Index Backup
  .MBX  Mailbox Message File (Outlook v1-4 or Eudora)
  .MCC  Mathcad Configuration
        Dialer10 Calling Card
        Monu-Cad Pro CAD File
  .MCD  Mathcad Document
        Monu-Cad Pro CAD File
  .MCF  Mathcad Font
  .MCI  Media Control Interface Command Set
  .MCL  Multimedia Manager Collection File
  .MCP  Mathcad Printer Driver
  .MCR  DataCAD Keyboard Macro File
  .MCS  MathCAD Format File
  .MCW  Word for Macintosh Text File
  .MCX  Graphic File
  .MD   Compressed Archive File 
  .MDA  MS Access Add-in
        MS Access 2 Workgroup
  .MDB  MS Access Database
        MS Access Application
  .MDE  MS Access Database File
  .MDF  Menu Definition File
  .MDL  Digitrakker Music Module (by n-FaCToR)
        Quake Model File
  .MDM  Telix Modem Definition
  .MDN  MS Access Blank Database Template
  .MDP  MS Developer Studio Project
  .MDT  MS Access Add-in Data
  .MDW  MS Access Workgroup Information
  .MDX  dBase IV Multiple Index
  .MDZ  MS Access Wizard Template
  .ME   Information (e.g., READ.ME)
  .MEB  WordPerfect Macro Editor Bottom Overflow File
  .MED  WordPerfect Macro Editor Delete Save
        OctaMED Tracker Module
  .MEM  WordPerfect Macro Editor Macro
        Memory File of Variables
        MS FoxPro Memory Variable Save File
  .MEN  Menu
  .MEQ  WordPerfect Macro Editor Print Queue
  .MER  WordPerfect Macro Editor Resident Area
        Data Interchange Format
  .MES  Message File
        WordPerfect Macro Editor Work Space
  .MET  WordPerfect Macro Editor Top Overflow File
        Presentation Manager Meta File
        OmniPage Document
  .MEU  DOS Shell Menus
  .MEX  Matlab Executable Command
        WordPerfect Macro Editor Expound File
  .MF   MetaFont Text File
  .MFF  MIDI File Format
  .MGC  MGCSoft Equation Editor File
  .MGF  Image File
        Micrografx Font
        Materials and Geometry Format File
  .MGM  MGCSoft Equation Editor Macro File
  .MH   Graphic File
  .MHG  Multimedia File
  .MHT  MS MHTML Document (Archived Web Page)
  .MI   Miscellaneous
  .MIC  MS Image Composer File
  .MID  MIDI File  [Viewer]
  .MIF  MIDI Instrument
        Adobe FrameMaker Interchange Format
  .MIL  Group 4 Fax File
  .MIM  Multi-Purpose Internet Mail Extensions (MIME) File  
  .MIX  Power C Object File
        Multilayer Picture File (MS PhotoDraw 2000 & MS Picture It!)
        Command & Conquer Movie/Sound File
  .MK   Make File
  .MKE  Make File
  .MKI  Picture File  
  .MLB  Macro Library  
  .MLI  Encyclopedia Media List
        3D Studio's Material-Library File
  .MLS  Miles Sound Tools Compressed DLS
  .MM   Macro Mania Macro
  .MMC  Media Catalog  
  .MME  Multi-Purpose Internet Mail Extensions (MIME) File
  .MMF  Meal Master Format
        MS Mail File
  .MMM  Animation MS Multimedia Movie
  .MMP  MindManager Player Play List File
  .MMS  Miles Sound Tools (Midi+DLS/MLS)
  .MMZ  MusicMatch Theme File
  .MN2  Descent2 Mission File
  .MN3  Descent3 Mission File
  .MND  AutoCAD Menu Program File
        MNI Mandelbrot for Windows
  .MNG  Animation Shop Animation
        Multi-image Network Graphics
  .MNT  Foxpro Menu Memo
  .MNU  Menu File (various)
  .MNW  Menu File (various)
  .MNX  AutoCAD Compiled Menu File
        Foxpro Menu
  .MNY  MS Money File
  .MOB  Device Definitions  
  .MOD  Music File
        ModuleA-2 Program File
        Windows Kernel Module
        Amiga and PC Tracker Module
        MS Multiplan Spreadsheet
  .MOV  QuickTime Video Clip  [Viewer]
        Apple QuickTime Audio
  .MOZ  Netscape Temp File
  .MP   Multiplan File
  .MP1  MPEG Audio Stream, Layer I
  .MP2  MPEG Audio Stream, Layer II
  .MP3  MPEG Audio Stream, Layer III  [Viewer]
  .MPA  MPEG Audio Stream, Layer I, II or III
  .MPC  MS Project Calender
  .MPD  Mini Port Driver
        MS Project Database File
  .MPE  MPEG Movie Clip
  .MPG  MPEG Animation  [Viewer]
        MPEG 1 System Stream
  .MPJ  RoboHTML Project
  .MPM  WordPerfect MathPlan Macro
  .MPP  MS Project File
        CAD Drawing File
  .MPQ  Blizzard Game Data File
  .MPR  Foxpro Program
  .MPS  Multimedia File
  .MPT  MS Project Template File
  .MPV  MS Project View
  .MPX  Foxpro Compiler Menu
        MS Project Export File
  .MRB  Multiple Resolution Bitmap Graphic
  .MRI  MRI Scan
  .MRK  Informative Graphics Markup File
  .MRS  WordPerfect Macro Resource File
  .MS   Checksum File for Anti-Virus
  .MSA  Magic Shadow Archive
  .MSG  Program Message
        OzWin Message/Mail File
        MS Mail Message
  .MSH  MASH (The Microsoft Agent Scripting Helper)
  .MSI  Windows Installer File
  .MSK  Autodesk Mask File
        PaintShop Pro Mask File
  .MSN  MS Network Document
        Descent Mission File
  .MSP  MS Paint Graphic File
        Windows Installer Patch
  .MST  Minispecification  
        Windows SDK Setup Script
  .MSW  Word Text File
  .MTH  Derive Math File
  .MTM  Sound File
        MultiTracker Music Module
  .MTV  Picture File
  .MTW  Minitab Data File
  .MU   Quattro Menu
  .MUL  Ultima Online Game
  .MUP  Music Publisher File
  .MUS  Audio File
  .MVB  Database
        MS Multimedia Viewer File
  .MVE  Interplay Video File [Descent2]
  .MVF  Movie Stop Frame File  
  .MWP  Lotus Wordpro 97 Smartmaster File
  .MXT  MS C
  .MYS  Myst Saved Game
  .MZ   MOZART Music Document
  .MZT  MOZART Template File

  .NAN  Nanoscope File
  .NAP  NAP Metafile Vector Image
  .NAV  MSN Application Extension
  .NB   Nota Bene Text File
  .NCB  MS Developer Studio File
  .NCD  Norton Change Directory
  .NCF  Netware Command File
        Lotus Notes Internal Clipboard
  .NDL  Lotus Notes
  .NDO  3D Low-polygon Modeler  
  .NDX  Index (usually dBase compatible)
  .NED  MSN Application Extension
  .NET  Network Configuration
        OrCad Netlist Output File
  .NEW  New Information (e.g., WHATS.NEW)
  .NFF  Image File
        Neutral File Format
  .NFO  Folio Infobase
  .NG   Norton Guide Online Documentation
  .NHF  Nero HFS-CD Compilation
  .NIL  Norton Icon Library File
  .NLB  Oracle 7 Data
  .NLM  Netware Loadable Module
  .NLS  Code Page National Language Support
  .NLU  Norton Live Update E-Mail Trigger File
  .NOL  Nokia Operator Logo
  .NOT  Notes
  .NOW  Text File (e.g., README.NOW)
  .NPM  Nokia Picture Message
  .NRA  Nero Audio-CD Compilation
  .NRB  Nero CD-ROM Boot Compilation
  .NRG  Norton Registration Entries
        Nero CD-Image
  .NRH  Nero Hybrid CD-ROM Compilation
  .NRI  Nero ISO CD-ROM Compilation
  .NRM  Nero Mixed-Mode-CD Compilation
  .NRT  Nokia RingTone
  .NRU  Nero UDF/ISO CD-ROM Compilation
  .NRV  Nero Video-CD Compilation
  .NS2  Lotus Notes 2 Database
  .NS3  Lotus Notes
  .NS4  Lotus Notes Database
  .NSF  Lotus Notes Database
  .NSG  Lotus Notes
  .NSH  Lotus Notes
  .NST  Audio File
        Noise Tracker Music Module
  .NSX  HiPer-Six Index File
  .NTF  Lotus Notes Database Template
  .NTS  Norton Tutorial
  .NTX  Clipper Index
  .NUF  Procomm Plus New User Message
  .NW   NoteWorthy 2 File
  .NWC  Noteworthy Composer Song File
  .NWS  MS Outlook Express News File

  .O    Object File (various)
  .O$$  Output File (temporary usually)
  .O01  Typhoon Voice File
  .OAB  MS Outlook Address Book
  .OAZ  OAZ Fax File  
  .OBD  MS Office Binder
  .OBJ  Relocatable Object Code (various)
        Lightwave Object
  .OBZ  MS Office Binder Wizard
  .OCA  Control Typelib Cache
  .OCX  Object Linking and Embedding (OLE) Control Extension
  .OD1  Omnis5 Database File (also .OD2, .OD3, etc.)
  .ODE  MS Office Object Data Embedding File
  .ODF  Open Document Interchange
        BattleZone Cartographers Guild File
  .ODL  Visual C++ Type Library Source
  .ODS  MS Outlook Express Mailbox
  .OFC  Open Financial Connectivity File

  .OFF  Vector Graphic (Object File Format)
        3D Mesh Object File Format
  .OFM  Adobe Font
  .OFN  MS Office FileNew File
  .OFT  MS Outlook Item Template
  .OFX  Open Financial Exchange File
  .OKT  Oktalyzer Tracker Module
  .OLB  Object Library
  .OLD  Old Version (sometimes used as a backup indicator)
  .OLE  Object Linking and Embedding (OLE) Object
  .OLI  Olivetti Text File
  .OMF  Image File
  .OND  Lotus Notes-related File (unverified)
  .ONX  Onyx Graphics Postershop File
  .OPC  Beta 44 Job File
  .OPJ  OrCad Project File
  .OPL  Psion Organiser Programming Language Source File
  .OPO  OPL Output Executable File
  .OPT  QEMM Optimize
        MS Developer Studio File
  .OPX  MS Orgchart Organization Diagram
        OPL Extension DLL
  .OQY  MS Excel OLAP Query File
  .OR2  Lotus Organiser 2 File
  .OR3  Lotus Organiser 97 File
  .ORA  Oracle 7 Configuration
  .ORC  MIDI File
        Oracle 7 Script
  .ORG  Lotus Organiser File
  .ORI  Original
  .OSS  MS Office Saved Search
  .OST  MS Exchange/Outlook Offline File
  .OTL  Super NoteTab Template File
  .OUT  Outlines or Output File (various)
  .OV1  Program File - Overlay
  .OV2  Program File - Overlay
  .OV3  Program File - Overlay
  .OVL  Program File - Overlay
  .OVR  Program File - Overlay
  .OZM  Sharp Organizer Memo Bank
  .OZP  Sharp Organizer Telephone Bank

  .P    PASCAL Program File
        Applause Picture
        Progress 4GL Program
  .P10  Tektronix Plot 10 Drawing
        Certificate Request
  .P65  Pagemaker 6.5 File
  .P7C  Digital ID File
  .P7M  PKCS #7 MIME Message (see Section 3.2 in RFC 2311
  .P7R  Certificate Request Response
  .P7S  PKCS #7 Signature
  .PAB  MS Personal Address Book
  .PAC  SB Studio II Package
  .PAD  Telemate Keypad Definition
  .PAG  Property Page File
  .PAK  Compressed Archive File
        Quake WAD File
  .PAL  Color Palette
        Adobe Pagemaker Library Palette
        Compressed File
  .PAN  Chromeleon Control Panel
  .PAR  Fractint Parameter File
  .PAS  Pascal Source Code
  .PAT  AutoCAD Hatch Pattern
        Corel Vector Pattern
        Advanced Gravis Ultrasound
        Forte Tech. Patch
  .PB   WinFax Pro Phone Book
  .PBD  PowerBuilder Dynamic Library
        Faxit Phone Book
  .PBF  Turtle Beach Pinnacle Bank File
  .PBK  MS Phonebook
  .PBL  PowerBuilder Library
  .PBM  UNIX Portable Bitmap
  .PBR  PowerBuilder Resource
  .PBI  Profiler Binary Input  
  .PBM  PBM Portable Bit Map Graphic  [Viewer]
  .PBO  Profiler Binary Output  
  .PBT  Profiler Binary Table  
  .PC   PC-specific Text File
  .PC3  Harvard Custom Palette (Harvard Graphics taken over by Serif)
  .PC5  Rockwell Software Logix 5 File
  .PC8  ASCII Text IBM-8
  .PCA  PCAnywhere Registry Backup
  .PCB  Protel Technology Advanced PCB Design
        MS PowerPoint Application Data File
  .PCC  Image File
  .PCD  Photo-CD Image  [Viewer]
        P-Code Compiled Test Scripts
  .PCE  Eudora Mailbox Name Map
  .PCF  Profiler Command File  
  .PCH  Patch File
        MS C PreCompiled Header
  .PCK  Turbo Pascal Pick File
  .PCL  HP-PCL Graphic Data File (HP Printer Control Language)
  .PCM  Sound File
        OKI MSM6376 Synth Chip PCM Format
  .PCP  Symantec Live Update Pro
  .PCS  PICS Animation
  .PCT  Bitmap Graphic (Apple PICT Format Usually)
  .PCW  PC Write Text File
  .PCX  PC Paintbrush Bitmap Graphic  [Viewer]
  .PDB  Palmpilot Database/Document File
        Pegasus DataBase
        Tact File
        QuickPOS Database File
  .PDD  Adobe PhotoDeluxe Image
  .PDF  Printer Description
        Adobe Acrobat File
        Netware Printer Definition File
        MS Package Definition File (Inventory-related)
  .PDG  PrintShop Deluxe File
  .PDI  MS Powerpoint File
  .PDQ  Patton & Patton Flowcharting PDQ Lite File
  .PDR  Port or Printer Driver
  .PDS  PDS Graphic
        Telsis HiCall Program File
  .PDT  ProCite Primary Database
  .PDV  Paintbrush Printer Driver
  .PDX  Paradox Files
        ProCite Database Keys
        Acrobat Catalog Index
  .PEB  WordPerfect Program Editor Bottom Overflow File
  .PED  WordPerfect Program Editor Delete Save
  .PEM  WordPerfect Program Editor Macro
  .PEQ  WordPerfect Program Editor Print Queue File
  .PER  WordPerfect Program Editor Resident Area
  .PES  WordPerfect Program Editor Work Space File
  .PET  WordPerfect Program Editor Top Overflow File
  .PF   Monitor or Printer Profile File
        Aladdin Systems Private Files Encrypted File
        Progress Parameter File
  .PFA  Outline Font (ASCII)
  .PFB  Outline Font (Binary)
  .PFC  PF Component
  .PFE  Programmers File Editor
  .PFK  XTree Programmable Function Keys
  .PFM  Printer Font Metrics
  .PFP  Panorama Factory Project File
  .PFR  PaintShop Pro File
  .PFT  Chiwriter Printer Font
  .PGL  Graphics (Plotter)
  .PGM  Portable Graymap Graphic  [Viewer]
        Chromeleon Batch Program
  .PGP  Program Parameter
        Pretty Good Privacy
  .PGX  Binary Property Page File
  .PH   PERL Header
        MS Help Compiler Phrase Table
  .PHD  PC Help Desk File
  .PHO  Phone List
  .PHP  PHP Script
        MS Picture It! Publishing Project File
  .PHR  NoExcuse Phrase Checker
        LocoScript Phrases
  .PIC  PC Paint Bitmap Graphic
        Lotus Picture
        Macintosh PICT Drawing
  .PIF  Windows Program Information File
        IBM PIF Drawing
  .PIG  Lucas Arts Dark Forces WAD File
  .PIM  PixMaker Project File
  .PIN  Pushpin Set
        Epic Pinball Data File
  .PIT  Macintosh Compressed Archive File
  .PIX  PrintMaster Graphic File
        Inset Systems Bitmap
  .PJ   MKS Source Integrity File
  .PJL  ProCite Term Lists and Journal Title Lists
  .PJT  Foxpro Project Memo
  .PJX  Foxpro Project
  .PKA  Compressed Archive File
  .PKB  QuickPOS (Point-Of-Sale) Keyboard Layout File
  .PKG  MS Developer Studio Application Extension
        AppleLink Package Compression Format File
  .PKO  PublicKey Security Object
  .PKR  PGP Public Keyring
  .PL   Harvard Palette (Harvard Graphics taken over by Serif)
        PERL Program File
  .PL3  Harvard Chart Palette (Harvard Graphics taken over by Serif)
  .PLB  Foxpro Library
  .PLB  LogoShow Screensaver
  .PLC  Lotus Add-in
  .PLD  PLD2 Source File (program due out 1Q2001)
  .PLG  REND386/AVRIL File
  .PLI  Oracle 7 Data Description
  .PLL  Prelinked Library
  .PLM  DisorderTracker2 Module
  .PLN  WordPerfect Spreadsheet File
  .PLR  Descent Pilot File
  .PLS  DisorderTracker2 Sample
        WinAmp MPEG PlayList File
        Shoutcast File
        MYOB Data File
  .PLT  AutoCAD HPGL Vector Graphic Plotter File
        Gerber Sign-making Software File
  .PLY  Autodesk Polygon
  .PM   PM Graphic or Perl Module
  .PM3  PageMaker 3 Document
  .PM4  PageMaker 4 Document
  .PM5  PageMaker 5 Document
  .PM6  PageMaker 6 Document
  .PML  NT4 Performance Monitor Log File
  .PN3  Harvard Printer Driver (Harvard Graphics taken over by Serif)
  .PNG  Public (Portable) Network Graphic (proposed GIF replacement)  [Viewer]
        PaintShop Pro Browser
  .PNM  PBM Portable Any Map Graphic
  .PNT  MacPaint File
  .POG  Descent2 File
  .POL  Music File
        AscToHTM Policy File
  .POP  dBase Popup Menu
  .POS  ProCite Output Styles
        QuickPOS IIF File (see IIF above)
  .POT  PowerPoint Template
  .POV  Persistence of Vision Ray-tracer
  .PP   Compressed Archive File
  .PP4  Picture Publisher
  .PP5  Picture Publisher
  .PPA  PowerPoint Add-in
  .PPB  WordPerfect Print Preview Button Bar
  .PPD  PostScript Printer Description
  .PPF  Turtle Beach Pinnacle Program File
        Jasc Paint Shop Pro 7 Preset File
  .PPI  MS PowerPoint Graphics File
  .PPL  Harvard Polaroid Palette Plus ColorKey Driver (Harvard Graphics taken over by Serif)
  .PPM  PBM Portable Pixelmap Graphic  [Viewer]
  .PPO  Clipper Preprocessor Output
  .PPP  Serif PagePlus Publication
        Parson Power Publisher
  .PPS  PowerPoint Slideshow
  .PPT  PowerPoint Presentation
  .PPX  Serif PagePlus Publication
  .PPZ  PowerPoint Packaged Presentation
  .PQ   Adobe Pagemaker Default Printer Style
  .PQI  Power Quest Drive Imaging Software
  .PR2  Persuasion Presentation
  .PR2  dBase IV Printer Driver
  .PR3  dBase IV PostScript Printer Driver
  .PRC  Palmpilot Resource File
  .PRD  Printer Driver
  .PRE  Freelance Presentation
  .PRF  Preferences File (various)
        dBase IV Printer Driver
        Profiler Output
        PICS Rules File
  .PRG  Program File (various)
        OzWin Purged Messages File
        WAVmaker Program
  .PRI  LocoScript Printer Definitions
  .PRJ  Project File
        3D Studio File
        HitPlayer Advanced Playlist File
  .PRM  Parameter File
  .PRN  Printer Text File
        DataCAD Windows Printer File
        XYWrite Printer Driver
        PostScript File
  .PRO  Profile
        PROLOG Program File
  .PRS  Printer Resource File
        WordPerfect Printer Resource Font File
        dBase Procedure
        Harvard File (Harvard Graphics taken over by Serif)
  .PRT  Printer  Configuration
        Printer-formatted File
        Unigraphics Part File (CAD modeling data)
  .PRV  PsiMail Internet Provider Template
        Previous Version (used for files that change)
  .PRX  Foxpro Compiler Program
  .PRZ  Freelance Graphics 97 File
  .PS   PostScript
  .PSB  Pinnacle Sound Bank
  .PSD  Photoshop Format  [Viewer]
        Apple Viewer File
  .PSF  Chiwriter PostScript Printer Font
  .PSI  PSION A-law Audio
  .PSM  Turbo Pascal Symbol Table
        Protracker Studio Module Format
        Epic Games Sound Data
  .PSP  PaintShop Pro Image  [Viewer]
  .PST  MS Outlook Personal Folder File
  .PSY  PLD2 System File (program due out 1Q2001)
  .PT3  Harvard Device Driver (Harvard Graphics taken over by Serif)
  .PT3  PageMaker Template
  .PT4  PageMaker Template
  .PT5  PageMaker Template
  .PTM  PolyTracker Music Module
  .PUB  PGP Public Key Ring
        Ventura Publication
        MS Publisher Document
  .PUF  Puffer Encrypted File
  .PW   Professional Write Text File
  .PWA  Password Agent File
  .PWD  Pocket Word Document
  .PWF  ProCite Workforms
  .PWL  Password List
  .PWP  Photoworks Image File
  .PWZ  PowerPoint Wizard
  .PX   Primary Index
  .PX   Paradox Primer Database Index
  .PXL  Pocket Excel Spreadsheet
  .PY   PYTHON Script
        Yahoo Saved Messages
  .PYC  Compiler PYTHON Script
  .PZD  Pizazz Plus File
  .PZO  Pizazz Plus File

  .Q9Q  BladePro Graphic Plugin File
  .QAD  PF QuickArt Document
  .QAG  Norton Desktop Quick Access Group
  .QAP  Omnis Quartz Application File
  .QBB  QuickBooks for Windows Backup File
  .QBD  Keyboard Layout
  .QBE  Example Query (Query By Example)
        dBase IV Saved Query
        Quattro Pro Saved Query
  .QBO  dBase IV Ordered Query
  .QBS  MS Quick Basic Program File
  .QBW  QuickBooks for Windows File
  .QCP  Qualcomm PureVoice File
  .QD?  Omnis Quartz Data File Segment (can be 0 to 9)
  .QDF  Quicken Data File
  .QDI  Dictionary
  .QDK  Quarterdeck QEMM File
  .QDT  QuickBooks UK Accountancy Data File
  .QEF  Excel Query
  .QEL  Quicken Electronic Library File
  .QEP  IRMA Wordstation for Windows
  .QFL  Family Lawyer Document
  .QFX  Quick Link Fax
  .QIC  Backup Set
  .QIF  Quicken Interchange Format
        QuickTime Image
  .QLB  MS C Quick Library
  .QLC  PostScript Help File
  .QLP  QuickLink Printer Driver
  .QM   Quality Motion File
  .QM4  QMail Mail Door Option or Services File
  .QMT  Quicken Memorized List
  .QNT  Chromeleon Quantification Method
  .QNX  Quicken Indexes
  .QPR  OS/2 Printer Queue Driver
        Foxpro Relational Query
  .QPW  Quattro Pro Project File
  .QPX  Foxpro Ordered Query
  .QQT  Quick Qard Technology Qardware Definition File
  .QRP  Centura Report Builder File
        Liberty for Windows Report File
  .QRS  WordPerfect Equation Editor
  .QRT  QRT Ray Tracing Graphic
  .QRY  dBase IV Query
        MS Query
  .QSC  Pxyl Visuals Chart
  .QSD  Quicken Datafile
  .QST  Quake Spy Tab File
  .QT   Quicktime Video
  .QTI  QuickTime Image
  .QTM  QuickTime Movie
  .QTP  QuickTime Preferences
  .QTS  Macintosh PICT Image
        QuickTime Image
  .QTX  QuickTime Image
  .QUE  Task Scheduler Queue Object
        CuteFTP Queue File
  .QW   Symantec Q&A Write Program File  [Support]
  .QWB  MS Money Quotes WriteBack Import File
  .QWK  QWK Reader Message File
  .QXD  QuarkExpress File
  .QXL  Quark Xpress Element Library
  .QXT  Quark Xpress Template File

  .R    Pegasus Mail Resource File
  .R??  RAR Compressed File (?? can be 01 to 99)
  .R8   RAW Graphic File
  .R8L  LaserJet Landscape Font
  .R8P  LaserJet Portrait Font
  .RA   RealMedia File  [Viewer]
  .RAM  RealMedia Metafile
  .RAR  RAR Compressed Archive
  .RAS  Sun Raster Graphic  [Viewer]
  .RAT  Rating System File
  .RAW  RAW RGB 24-bit Graphic
        Raw Signed PCM Data
  .RAX  Image File
  .RB   RocketEdition File
  .RBF  R:Base Data File
  .RBH  RoboHelp Configuration
  .RC   Borland C++ Resource Compiler Script File
  .RD1  Descent1 Registered Level File
  .RD3  Ray Dream Designer Graphics
        CorelDream 3D
  .RD4  Ray Dream Designer Graphics
  .RD5  Ray Dream Designer Graphics
  .RDB  TrueVector Rules Database
  .RDF  Resource Description Framework File
        Chromeleon Report Definition
  .RDL  Descent Registered Level
  .RDX  Reflex Data File
  .REC  Sprint Record File
        Windows Recorder Macro
        RapidComm Voice File
  .REF  Cross Reference
  .REG  Registration Data
  .REM  Annotation (remark)
  .REP  Text Document
  .REQ  Request
  .RES  Resource File (various programs)
  .REX  REXX Program File
        Oracle Report Definition
  .REZ  Resources
  .RF   Sun Raster Graphic
        RealFlash Clip
  .RFD  RecogniFORM Form Definition
  .RFG  RFG Integrator System Database
  .RFH  RFG Integrator Householding Database
  .RFT  Revisable Format Text
  .RGB  Picture File
  .RI   Lotus File
  .RIA  Alpharel Group IV Raster Graphics File
  .RIC  Ricoh Graphic File
  .RIF  Fractal Painter Bitmap
  .RIP  Remote Imaging Protocol
  .RIX  Colorix File
        RIX Virtual Screen
  .RL1  Descent1 Registered Level File
  .RL2  Descent2 Registered Level
  .RLA  Advanced Visualizer File
        Wavefront Raster Image
  .RLB  Harvard Graphic File (Harvard Graphics taken over by Serif)
  .RLC  Image Systems CAD Overlay
  .RLE  Graphic (Run Length Encoded)  [Viewer]
  .RM   RealMedia File
  .RMD  RegMaid Document
  .RMF  Rich Map Format (3D Games)
  .RMI  MIDI File  [Viewer]
  .RMK  RMake Make File
  .RMM  RealPlayer File
  .RND  AutoCAD Rendering Slide
        AutoShade Format
  .RNL  GTX Runlength Raster Graphics
  .RNX  RealPlayer File
  .ROL  Adlib Music
  .ROV  Rescue Rover Data
  .RP   RealPix Clip
  .RPD  Rapidfile Database
  .RPM  RedHat Package Manager (Linux)
        RealMedia Player File
  .RPT  Report (various)
  .RQY  MS Excel OLE DB Query File
  .RR   Railroad Tycoon
  .RRS  Road Rash Save File
  .RSB  Rogue Spear Bitmap
  .RSL  PC Tools Resources Library
        Borland's Paradox 7 Report
        Adobe Pagemaker File
  .RSP  Responce Text File
        Rockwell Software Logix 5 File
  .RT   RealText Clip
  .RTA  RoboHelp Configuration
  .RTF  Rich Text Format
  .RTK  RoboHelp Configuration
  .RTL  Text File
  .RTM  Real Tracker Music Module
  .RTP  TurboTax Update File
  .RTS  RoboHelp Configuration
        RealAudio RTSL Document
  .RUL  InstallShield
  .RUN  PC Tools Script Tools Program
  .RV   RealVideo Clip
  .RVP  Microsoft Scan Configuration File
  .RX   Reflex Database Driver
  .RXD  Reflex Database
  .RXH  Reflex Database Help File
  .RXR  Reflex Database Report
  .RXS  Reflex Database Screen Driver

  .S    Assembler Source Code
  .S$$  Temporary Sort File
  .S01  WordPerfect Distribution File
  .S02  WordPerfect Distribution File
  .S03  WordPerfect Distribution File
  .S2P  Sonnet File
  .S3I  ScreamTracker v3 Instrument
  .S3M  ScreamTracker v3 Module
        ScreamTracker v3 Sound File
  .SAD  Serveron Analyzer Data File
  .SAH  SETI@Home Data File
  .SAM  Ami Pro Text File
        Signed 8-bit Sample Data
  .SAN  The Curse of Monkey Island Movie File
  .SAV  Backup
        Saved File
  .SB   Audio File
        Raw Signed Byte (8-bit) Data
  .SBK  Emu SoundFont v1.x Bank Files
        Creative Labs SB AWE 32
  .SBL  Shockwave Flash Object
  .SBP  Superbase DML Program
  .SC   Framework Screen Driver
        Paradox Source Code
        Ingres Embedded SQL/C Source File
  .SC2  Sample Cell
        II PC Instrument
        Schedule+ File
        SAS Catalog
  .SC3  Harvard Screen Driver (Harvard Graphics taken over by Serif)
  .SCC  Text File
        Stamp Collector's Girl Friday Catalog File
        Source Safe File
  .SCD  Graphic (SCODL Scan Conversion Object Description Language)
        Schedule+ File
        TurboTax Schedule File
  .SCE  SoftCuisine Data Exchange File
  .SCF  Windows Explorer Command
  .SCH  Schedule+ File
        EAGLE Schematic File
        OrCad Schematics File
  .SCI  ScanVec Inspire File
  .SCL  SCALA Scale
  .SCM  SchematicMaker (Topanga Software) File
        ScreenCam Movie
  .SCN  Compressed Screen format
        TrueSpace2 Scene
  .SCO  High Score (various)
  .SCP  Script (various)
  .SCR  Faxview Fax
        Screen Saver
        Procomm Plus Screen Snapshot File
        LocoScript Screen Font File
  .SCT  Foxpro Screen
        PC Tools Script Tools
        Scitex Continuous Tone Bitmap
        SAS Catalog
        Windows Script Component
        Lotus Screen Capture Text
  .SCV  ScanVec CASmate File
  .SCX  MS FoxPro Screen File
        Image File
  .SD   Sound Designer I Audio
  .SD2  Sound Designer II Flattened File
        Sound Designer II Data Fork
        SAS Database
  .SDA  StarOffice Drawing
        SoftCuisine Data Archive
  .SDC  StarOffice Spreadsheet
  .SDD  StarOffice Presentation
  .SDF  Standard Data Format
        Schedule Data File
        System File Format
        Autodesk MapGuide Spatial Data Files
  .SDK  Roland S-series Floppy Disk Image
        Autosketch Drawing
  .SDL  SmartDraw Library
  .SDN  Shell Archive
  .SDR  SmartDraw Drawing
  .SDS  StarOffice Chart
        Raw Midi Sample Dump Standard File
  .SDT  SmartDraw Template
  .SDV  Semicolon Divided Values File
  .SDW  StarOffice Text
        Raw Signed DWord (32-bit) Data
        Lotus WordPro Graphic
  .SDX  Midi Sample Dump Standard Files Compacted by SDX
  .SEA  Macintosh Compressed Archive File
  .SEC  Compressed Archive File
        PGP Secret Key Ring
  .SEG  Compressed File Segment
  .SEL  PaintShop Pro Selection File
  .SEP  TIFF Bitmap Separation
  .SEQ  Animation File
        Chromeleon Sequence List
  .SES  Digital Audio Editor File
  .SET  Driver Set
        Image Settings
        Backup File Set
        Configuration (various)
  .SEX  Urban Chaos Game File
  .SF   Sound File
        OS/2 WPS Attribute Storage
        IRCAM SoundFile
  .SF2  Emu SoundFont v2.0 File
        Creative Labs Soundfont 2.0 Bank File
  .SFD  SoundStage Sound File Data
  .SFI  Ventura Printer Font
        SoundStage Sound File Info
  .SFL  Ventura Printer Font
        LaserJet Landscape Font
  .SFP  Ventura Printer Font
        LaserJet Portrait Font
  .SFR  Sonic Foundry Sample Resource
  .SFS  StarOffice Frame
        PCL 5 Scalable Font
  .SFT  Chiwriter Screen Font
  .SFW  Graphic File (Seattle Film Works)  [Viewer]
  .SFX  Self-extracting Archive
  .SGF  Smart Game Format
  .SGI  Graphic File  [Viewer]
  .SGL  StarOffice Master Document
  .SH   Archive File
  .SH3  Harvard Presentation (Harvard Graphics taken over by Serif)
  .SHB  Corel Background File
        Document Shortcut File
  .SHG  Hotspot Editor Hypergraphic
  .SHK  Macintosh Compressed Archive File
  .SHM  WordPerfect Shell Macro
  .SHP  3D Studio Shapes File
        3D Modeling File (various)
  .SHR  Archive File
  .SHS  Shell Scrap Object File
  .SHW  Corel Presentation
        WordPerfect Slide Show
        Show File
  .SI   SoftImage Image File
  .SIB  Sibelius Music File
  .SIG  Signature File
  .SIK  Backup File
  .SIM  Simulation
  .SIT  Macintosh Compressed Archive File
  .SIZ  Oracle 7 Configuration
  .SKA  PGP Secret Keyring
  .SKB  QuickPOS (Point-Of-Sale) Standard Keyboard Layout File
  .SKL  Authorware Resource
  .SKN  FileWrangler/SecurDesk!/ImageForge Graphic Skin
        eRocket eBook Skin
  .SL   S-Lang Program File
        PACT's Save Layout
  .SLB  AutoCAD Slide Library
  .SLC  Telix Compiler SALT Script
  .SLD  AutoCAD Slide
  .SLG  Chromeleon Audit Trail
  .SLK  Data Exchange File (Symbolic Link)
  .SLT  Telix SALT Script Application
  .SM   Smalltalk Program File
  .SM   Samna Word Text File
  .SM3  DataCAD Symbol File
  .SMD  StarOffice Mail
  .SMF  StarOffice Formula
  .SMI  RealPlay SMIL File
  .SMK  Smacker Compressed File
  .SMM  Ami Pro Macro
  .SMP  Sample or Samplevision Format
        Ad Lib Gold Sample
  .SMT  HiPer-Six Memo File
  .SND  Sound Clip  [Viewer]
        Raw Unsigned PCM Data
        AKAI MPC-series Sample
        NeXT Sound
        Macintosh Sound Resource
  .SNG  MIDI Song
  .SNM  Netscape Mail
  .SNO  SNOBOL Program File
  .SNP  Shapshot file (Snapview)
  .SOU  SB Studio II Sound
  .SP   Compressed Archive File
  .SPC  Multiplan Program
        WordPerfect Temp File
        SNES Audio file
  .SPD  Harvard Bitstream Typefaces (Harvard Graphics taken over by Serif)
        PostScript Printer
        Speech Data File
        Speedo Scalable Font
  .SPG  Sprint Glossary
  .SPL  Compressed Archive File
        Printer Spool File
        Sprint Printer Driver
        Sample File
        Spell Checker
        Digitrakker Sample (by n-FaCToR)
        Shockwave Flash Object
  .SPM  WordPerfect File
  .SPN  WordPerfect Distribution File
  .SPP  Sprint Printer File
  .SPR  Sprint Document Letter
        Foxpro Generated Screen Program
  .SPS  Sprint Screen Driver
  .SPT  SPITBOL Program File
  .SPW  SigmaPlot Worksheet
  .SPX  Foxpro Compiler Screen Program
        Screen Peace Extension
  .SQB  SyQuest Backup
  .SQC  Structured Query Language Common Code File 
  .SQL  Structured Query Language Data 
  .SQR  Structured Query Language Program File  
  .SQZ  Compressed Archive File
  .SRC  Sourcecode (various)
  .SRF  Sun Raster Graphic File
  .SSD  SAS Database
  .SSF  Enable Spreadsheet File
  .SSI  Installer/GD Software Setup Information
  .SSM  RealPlay Standard Streming Metafile
  .SST  Certificate Store
  .ST   SMALLTALK Program File
        Atari ST Disk Image
        NeoPaint Stamp File
  .STA  Eudora File
  .STB  Genus Stub Library
  .STD  State Transition Diagram Graphic
        SureThing CD Labeler Document
        LocoScript Standard Script File
  .STF  Compressed Archive File
        Setup Information
        Structured File
  .STG  PageKeeper Storage File
  .STK  Personal Stock Monitor File
  .STL  Certificate Trust List
        CAD Software Solid Modeling/Prototyping File
  .STM  Sound File
        State Transition Diagram Model
        Scream Tracker v2 Module
        SHTML File
  .STO  Genus Pascal Stub OBJ File
  .STP  PageKeeper Packed Storage File
  .STR  dBase Structure List
        DataPerfect Structure File
        Stream File (Playstation Discs)
  .STS  MS C Project Status Info
  .STY  Style Sheet
        MS Interactive Music Control
        LaTeX2e Style
  .SUD  Super Project Analyzer Data
  .SUN  Sun Raster Graphic File
  .SUP  WordPerfect Supplemental Dictionary
        Super Porject Analyzer Project
  .SVD  Word Backup File
  .SVG  Word Backup File
        Scalable Vector Graphics File
  .SVS  Word Backup File
  .SVX  Interchange File Format, 8SVX/16SV
        Amiga 8SVX Sound
  .SW   Audio File
        Raw Signed Word (16-bit) Data
  .SWA  Shockwave Audio File
  .SWD  Storybook File (educational)
  .SWF  Macromedia Flash Format  [Alternate]  [Viewer]
  .SWI  Swish Data File
  .SWL  Macromedia Flash Format  [Alternate]
  .SWP  Sprint Backup File
        Swap File
  .SWT  VB Setup Wizard Template File
        Space Watch Pro Data File
  .SY3  Harvard Symbol File (Harvard Graphics taken over by Serif)
  .SYD  Sysedit Backup File
  .SYL  SYLK Spreadsheet Format
  .SYM  Symbol Table (various)
  .SYN  Synonym File
  .SYS  System Configuration
        System Device Driver
  .SYW  Harvard Symbol Graphic (Harvard Graphics taken over by Serif)
        Yamaha SY-series Wave Files

  .T??  Ingres Table/Index File (?? = Hex 00 to FF)
  .T2T  Sonata CAD Modelling File
  .TAB  Guitar Tablature File
  .TAG  Dataflex Query Tag Name
  .TAH  Turbo Assembler Help File
  .TAL  Adobe TypeAlign Text Illustration File
  .TAR  Compressed Archive File
  .TAX  Turbotax File
  .TAZ  TAR.Z Compressed File
  .TB1  Turbo C Font
  .TB2  Turbo C Font
  .TBK  Memo Backup (database programs)
        Asymetrix Toolbook
  .TBL  Adobe Pagemaker Import Mapping Table
  .TC   Borland Configurations File
  .TCH  Borland Help File
  .TCL  TCL/TK Language Script
  .TD   Turbo Debugger Configurations File
  .TDB  Thumbs Plus Database
  .TDF  Trace Definition File
        Typeface Definition File (for fonts)
  .TDH  Turbo Debugger Help File
  .TDK  Turbo Debugger Keyboard Record
  .TDO  Compressed File
  .TDP  Serif DrawPlus Thumbnail
  .TDS  Turbo Debugger Symbol Table
  .TEM  Icon Author Template
        Turbo Editor Macro Language
  .TEX  TeX
        LaTeX File
        Texture File
  .TF   Turbo Profiler Configuration File
  .TFA  Turbo Profiler Area File
  .TFH  Turbo Profiler Help File
  .TFM  Tagged Font Metric
  .TFS  Turbo Profiler Statistic
  .TG4  CCITT Group 4 Fax
  .TGA  Truevision Targa Graphic  [Viewer]
  .TGH  TrueGas Host File
  .TGZ  UNIX Tar File Zipped
  .THB  Bitmap Graphic
  .THD  Thread
  .THM  MS Clipart Gallery Database
        Serif DrawPlus Theme
  .THN  Graphics Workshop for Windows Thumbnail
  .THP  TurboTax-related File
  .THS  WordPerfect Thesaurus
  .TIF  Tagged Image Format File [Viewer]
  .TIG  Tiger Government Map File
  .TLB  Remote Automation Truelib Files
        OLE Type Library
        Visual C++ Type Library
  .TLD  Trellix File
  .TLE  NASA Two-Line Element Set
  .TLP  MS Project Timeline File
  .TLT  Trellix Web Design File
  .TLX  Telex
        Trellix Data File
  .TMF  WordPerfect Tagged Font Metric File
  .TMO  Zortech C++ Global Optimizer Output File
  .TMP  Temporary File
  .TMS  Telemate Script
  .TOC  Eudora Table Of Contents
  .TOL  Kodak Photoenhancer
  .TP   Turbo Pascal Configuration File
  .TP3  Harvard Template (Harvard Graphics taken over by Serif)
  .TPH  Turbo Pascal Help File
  .TPL  Turbo Pascal Resident Units
        Harvard Template (Harvard Graphics taken over by Serif)
        fKey Template Designer Template File
        CakeWalk Audio Template File
        DataCAD Template File
  .TPP  Turbo Pascal Protected Mode Units
        Teleport Pro Project
        TypePlus File
  .TPU  Turbo Pascal Unit
  .TPW  Turbo Pascal Unit
  .TRE  PC Tools Directory Tree
  .TRK  Kermit Script File
  .TRM  Terminal Settings (various)
        TRiM High-compression Lossless 8 to 32 bit Truecolor Image File
  .TRN  Quattro Translation
        Adobe Pagemaker File
        MKS Source Integrity Project Log
  .TRP  Tripmaker File
  .TS   Tune Smithy File
  .TSP  Windows Telephony Service Provider
  .TST  WordPerfect Printer Test File
        Test File
  .TTC  TrueType Compressed Font
  .TTF  TrueType Font
  .TTK  Corel Catalyst Translation Tool Kit
  .TTL  Tera Term Macro File
  .TUB  PaintShop Pro Tube File
  .TUT  Tutorial
  .TWF  TabWorks File
  .TWW  Tagwrite Template
  .TX8  DOS Text File
  .TXB  Descent/D2 Encoded Briefing File
  .TXC  Urban Chaos Game File
  .TXT  Text File
  .TXW  Yamaha TX16W Wave Files
  .TXX  DataPerfect Text Storage
  .TYM  PageMaker Time Stamp
  .TZ   Compressed File
        Ingres Time Zone File

  .U96  EasyZip Temporary File
  .UAP  User Agent Wireless Telephony Profile
  .UB   Audio File
        Raw Unsigned Byte (8-bit) Data
  .UC2  Compressed File  
  .UCM  Urban Chaos Game File
  .UCN  Compressed Archive 
  .UDF  WindowsNT Uniqueness Database File
        Photostyler Image Filter
  .UDL  MS Data Link
  .UDW  Raw Unsigned DoubleWord (32-bit) Data
  .UE2  Encrypted Archive 
  .UFO  Ulead Object File
  .UG   Drawing File (various)  
  .UHS  Universal Hint System File
  .UI   User Interface
        Geoworks UI Compiler Espire Source
  .UIF  WordPerfect Long Prompts
  .UIH  Geoworks UI Compiler Espire Header
  .UL   uLAW Audio File
  .ULD  Procomm Uploaded Files
  .ULS  Internet Location Service
  .ULT  UltraTracker Music Module
  .UMB  MemMaker Backup Archive
  .UNI  MikMod (UniMod) Format
        Forcast Pro Data File
  .UNX  Text File (usually UNIX)
  .UPD  dBase Update File
        Universal Print Driver (cross-platform)
        Updated Program Data (various)
  .UPI  ULead Photo Impact Program File
  .UPO  dBase Compiled Update File
  .UPX  ULead Photo Express Saved Image File
  .URF  Radar ViewPoint Universal Radar Format
  .URL  Internet Location
  .USE  MKS Source Integrity File
  .USL  LaserJet Landscape Font
  .USP  PageMaker Printer Font
        LaserJet Portrait Font
  .USR  User Database (various)
  .UTL  Sound File
  .UTP  BinPatch Patch Data File
  .UU   Compressed Archive File (UUENCODE)
  .UUD  Uudecoded
  .UUE  Uuencoded
  .UW   Audio File
        Raw Unsigned Word (16-bit) Data
        Unitype GlobalWriter File
  .UWF  UltraTracker Wave File

  .V8   Covox 8-bit Audio
  .VAL  Validity Checks
        dBase Values
  .VAP  Annotated Speech
  .VAR  Icon Author Variable
  .VBA  VBase File
  .VBG  Visual Basic Group Project
  .VBK  VisualCADD Backup File  [Support Group]
  .VBL  User Control Licensing File
  .VBP  Visual Basic Project
  .VBR  Remote Automation Registration Files
  .VBS  VBScript Script File
  .VBW  Visual Basic Project Workplace
  .VBX  Visual Basic Extension
  .VBZ  Wizard Launch File
  .VC   VisiCalc Spreadsheet File
  .VCD  VisualCADD Drawing File  [Support Group]
  .VCE  Natural MicroSystems Voice File
  .VCF  vCard File
        Vevi Configuration File
  .VCS  MS Outlook vCalendar File
  .VCT  FoxPro Class Library
  .VCW  MS Visual C++ Workbench Information File
  .VCX  FoxPro Class Library
        Spreadsheet File
  .VDA  Targa Bitmap
  .VDO  VDOScript File
  .VEW  Clipper Viewfile
        Lotus Approach View File
  .VGA  VGA Screen Driver
        Targa Bitmap
  .VGR  Ventura Graphic
  .VI   Virtual Instrument LabView File
  .VIB	Chemsoft® Export/Import MSDS Data
  .VIC  Vicar Picture File
  .VID  Monitor Control File
        Screen Driver
  .VIK  Viking Picture File
  .VIR  Virus Infected File (renamed by Symantec Anti-Virus)
  .VIS  Picture File
  .VIV  VivoActive Player Video File
  .VIZ  Division dVS/dVISE File
  .VLB  Corel Ventura Library
  .VMF  Ventura Font Characteristics
        FaxWorks Audio File
  .VOB  DVD Video Movie File
  .VOC  Quartet Audio File
        Creative Labs Sound
  .VOX  Vox Audio
        Dialogic ADPCM
        Talking Technology Inc. File
        Natural MicroSystmes Voice File
  .VP   Ventura Publisher File
  .VQE  Yamaha Sound-VQ Locator File
  .VQF  Yamaha Sound-VQ File
  .VQL  Yamaha Sound-VQ Locator File
  .VRF  Oracle 7 Configuration File
  .VRS  WordPerfect Graphics Driver
  .VS2  Roland-Bass Transfer File
  .VSD  Visio Drawing
  .VSL  GetRight Download List File
  .VSS  Visio Stencil
  .VST  Visio Template
        Truevision Vista Graphic
        Targa Bitmap
  .VSW  Visio Workspace File
  .VUE  dBase or Foxpro View
  .VVF  ViVerify Fingerprint
  .VVR  ViVerify Repair
  .VW   Volkswriter Text File
  .VWF  CADvance Drawing File
  .VWR  PC Tools File Viewer
  .VXD  Virtual Device Driver

  .W    Applause Word Chart
  .W30  Ventura Printer Font
  .W3D  Black Belt Systems Ray Trace Control File
  .W40  Win95 Backup File
  .WAB  MS Outlook File
  .WAD  Doom Game File
  .WAL  WalMaster Showlist File
        Quake 2 Texture File
  .WAS  Procomm Plus Script Source Code File
  .WAV  Waveform Audio (PCM Wave)  [Viewer]
  .WAX  Procomm Plus Compiled Script File
  .WB1  QuattroPro for Windows
  .WB2  QuattroPro for Windows
  .WBF  Windows Batch File
  .WBK  Word Backup
        WordPerfect Workbook
  .WBL  Argo WebLoad II Upload File
  .WBR  Crick WordBar File
  .WBS  WebExpress Website File
  .WBT  WinBatch Script
        Crick Wordbar Template
  .WCD  WordPerfect Macro Token List
  .WCM  Works File Transmission
        WordPerfect Macro
  .WD2  WordExpress Document
  .WDB  Works Database
  .WDK  WhizFolder Desktop File
  .WEB  Web Vector Graphic File
        Corel Xara Web Document
  .WFB  Turtle Beach WaveFront Bank
  .WFD  Turtle Beach WaveFront Drum Set
  .WFN  Corel Symbols and Fonts
  .WFP  Turtle Beach WaveFront Program
  .WFX  Winfax Data File
  .WG1  Lotus 1-2-3 Worksheet
  .WG2  Lotus 1-2-3 Worksheet
  .WGP  Wild Board Games File
  .WHT  MS NetMeeting Old Whiteboard Document
  .WID  Ventura Width Table
  .WIF  Weaving Information Format
        Wavelet Image File
  .WIL  Windows Interface Language Script
        WinImage File
  .WIN  dBase or Foxpro Window
        Windows Backup File
  .WIZ  Wizard File [MS Publisher and Word]
  .WK1  Lotus Spreadsheet File
  .WK3  Lotus Spreadsheet File
  .WK4  Lotus Spreadsheet File
  .WKB  WordPerfect Document
  .WKB  Workbook
  .WKE  Lotus Educational Version Spreadsheet File
  .WKQ  Quattro Spreadsheet
  .WKS  Lotus Spreadsheet File
        XLISP Workspace
        Works Document
  .WKZ  Compressed Spreadsheet
  .WLD  REND386/AVRIL File
  .WLF  Argo WebLoad I Upload File
  .WLG  Dr. Watson Log
  .WLL  Word Add-in
  .WLR  VRML Page
  .WLS  602 pro PC SUITE Worksheet File
  .WMA  MS Active Streaming (Media) File  
  .WMC  WordPerfect Macro
        Wordmarc Text File
  .WMF  Windows Metafile  [Viewer]
  .WMV  MS Active Streaming (Media) File
  .WN   Write Now Text File   
  .WNF  Corel Outline Font
  .WOA  Windows Swap File
  .WOW  Grave Composer Music Module
  .WP   WordPerfect Document File
  .WP4  WordPerfect Document File
  .WP5  WordPerfect Document File
  .WP6  WordPerfect Document File
  .WPD  WordPerfect Screen Driver or Document
        602 pro PC SUITE Document File
  .WPF  WordPerfect Text File
        Enable Document
  .WPG  WordPerfect/Drawperfect Graphics
  .WPK  Keyboard
        WordPerfect Macros
  .WPM  WordPerfect Macro
  .WPS  Works Text Document
  .WPT  WordPerfect Template
        602 pro PC SUITE Template Document File
  .WPW  PerfectWorks Document  
  .WQ!  Quattro Pro Compressed Spreadsheet
  .WQ1  Quattro Pro Spreadsheet
  .WQ2  Quattro Pro Spreadsheet
  .WR1  Symphony Spreadsheet File
  .WRD  Charisma Template
  .WR1  Symphony Document
  .WRI  Write Document
  .WRK  Spreadsheet File
        Cakewalk Music Project File
  .WRL  Plain Text VRML File
  .WRP  Amiga Compressed Archive File
  .WRS  WordPerfect Windows Printer Driver
  .WRZ  GNUZIP Compressed VRML File 
  .WS   WordStar Document
  .WS1  WordStar for Windows 1 Document
  .WS2  WordStar for Windows 2 Document
  .WS3  WordStar for Windows 3 Document
  .WS4  WordStar for Windows 4 Document
  .WS5  WordStar for Windows 5 Document
  .WS6  WordStar for Windows 6 Document
  .WS7  WordStar for Windows 7 Document
  .WSC  Windows Script Component
  .WSD  WordStar Data File
  .WSE  Wise File
  .WSH  Windows Script Host Settings File
  .WSP  Chromeleon Wordspace
  .WSQ  Wavelet-packet Scalar Quantization
  .WST  WordStar Text File
  .WT2  WordExpress Document Template
  .WVL  Wavelet Compressed Bitmap
  .WWL  Word Add-in File
  .WZD  Sharp Organizer Program or Data File
  .WZN  WhizFolder Document

  .X    LEX Program File
        AVS Image   
  .X01  Paradox Secondary Index (can be 01 to 09)
  .X16  Macromedia Program Extension (16-bit)
  .X32  Macromedia Program Extension (32-bit)
  .X5   Rockwell Software Logix 5 File
  .XA   Extended Architecture File
        File on PSX Disc
  .XAB  Xenis Mail Address Book
  .XAR  Corel Xara Drawing
  .XBM  X Bitmap Graphic  [Viewer]  
  .XFN  Ventura Printer Font
  .XFT  Chiwriter 24 Pin Printer Font
  .XFX  Fax File (various)
  .XI   Fast Tracker 2 Instrument
        ScreamTracker Instrument File
  .XIF  Wang Image File
        Xerox Image File
  .XLA  Excel Add-in
  .XLB  Excel File
  .XLC  Excel Chart
  .XLD  Excel Dialog
  .XLG  Xnetech Engraving Logo File
  .XLK  Excel Backup
  .XLL  Excel Add-in (Dynamic Link Library)
  .XLM  Excel Macro
  .XLS  Excel Worksheet
  .XLT  Excel Template
        Procomm Plus Translation Table
        Lotus Translation Table
  .XLV  Excel VBA
  .XLW  Excel Workspace
  .XM   Sound File
        Fast Tracker 2 Extended Module
  .XML  Extensible Markup Language File  
  .XNK  Exchange Shortcut
  .XOT  Xnetech Job Output File
  .XPM  X Picsmap Graphic  [Viewer]
  .XQT  SuperCalc Macro Sheet
  .XRF  Cross Reference
  .XR1  Epic MegaGames Xargon File
  .XSL  XML Stylesheet 
  .XT*  Crosstalk Related File
  .XTB  LocoScript External Translation Table
  .XWD  X Windows Dump  
        Crossdown Puzzle File
  .XWF  Yamaha XG Works File
  .XXE  Xxencoded File
  .XY   XYWrite Text File
  .XY3  XYWrite Text File
  .XY4  XYWrite IV Document
  .XYP  XYWrite III Plus Document
  .XYW  XYWrite Windows 4.0 Document

  .Y    Amiga Yabba Compressed Archive File
        Yaac Grammar File
  .Y01  Paradox Secondary Index (can be 01 to 09)
  .YAL  Arts & Letters Clipart
  .YBK  Encarta Yearbook
  .YUV  Color Space Pixel Format
  .YZ   Yac Compressed Archive File

  .Z    Compressed Archive File
  .Z?   See .ZL? Below
  .Z3   Infocom Game Module
  .ZAP  FileWrangler Compressed File (only used in beta)
        MS Windows Software Installation Settings
  .ZC   Zipkey Configuration File
  .ZDG  ZView Compressed Document
  .ZER  Zerberus File
  .ZFS  C++ Assembly Source
  .ZGM  ZenoGraphics File
  .ZIP  Compressed Archive File
  .ZL?  ZoneAlarm Mailsafe Renamed File
        ZoneAlarm Mailsafe will quarantine mail attachments and changes
        their extension. The conversions are: .ADE to .ZL0, .ADP to .ZL1
        .BAS to .ZL2, .BAT to .ZL3, .CHM to .ZL4, .CMD to .ZL5, .COM to
        .ZL6, .CPL to .ZL7, .CRT to .ZL8, .EXE to .ZL9, .HLP to .ZLA,
        .HTA to .ZLB, .INF to .ZLC, .INS to .ZLD, .ISP to .ZLE, .JS to Z0,
        .JSE to .ZLF, .LNK to .ZLG, .MDB to .ZLH, .MDE to .ZLI, .MSC to
        .ZLJ, .MSI to .ZLK, .MSP to .ZLL, .MST to .ZLM, .PCD to .ZLN,
        .PIF to .ZLO, .REG to .ZLP, .SCR to .ZLQ, .SCT to .ZLR, .SHS to
        .ZLS, .URL to .ZLT, .VB to .Z1, .VBE to .ZLU, .VBS to .ZLV,
        .WSC to .ZLW, .WSF to .ZLX, .WSH to .ZLY [Documentation]
  .ZOM  Amiga Compressed Archive File
  .ZOO  Compressed Archive File
  .ZVD  ZyXEL Voice File
  .ZW   Chinese

  .~    Temporary File
  .~AP  Borland C++ AppExpert Project Database File
  .~DE  Borland C++ Project Backup File
  .~MN  Norton Menu Backup
  .~PR  Terramodel Project Backup
  .~SG  TapCIS Message Index File
  .~$~  1st Reader Temporary File