A list of file extensions and what they are used for and what they mean.
Written by Allan, Jan 2004
Font Mapping Table. AutoCAD comes with a default font mapping table in the acad.fmp file in the Support folder. You can edit this file using any ASCII text editor. You also can specify a different font mapping table file in the Options dialog box, or you can specify the font mapping file using the FONTMAP system variable.
linetype definition files. AutoCAD linetypes are composed of a series of dots and dashes separated by spaces, and can contain embedded shape and text objects. The default linetype file is acad.lin. You can print this file to better understand how to construct linetypes.
Multiline definition. Multiline styles control the number of line elements in a multiline and the color, linetype, lineweight, and offset from the multiline origin of each element. You can change any of these properties. You can also modify the display of joints, end caps, and background fill. A modified multiline style retains the changes permanently.
Hatch pattern definition. Hatch patterns can be created or modified in these types of files.
Program Parameters. Use keyboard shortcuts such as L for LINE to start your favorite commands. Create your own keyboard shortcuts by modifying the acad.pgp file located in the Support directory. You can use any standard text editor to edit the acad.pgp file.
The AutoCAD PostScript Support file (acad.psf) is the master support file for AutoCAD PSOUT and PSFILL commands.
Unit definition file. The acad.unt file contains data that lets you convert from one set of units to another.
Geographic continent files. These files provide geographical location information (such as latitude and longitude) in ASCII format for use with the lighting feature available under the RENDER command.
An un-complied or source shape/font file. Compiling a shape definition file (SHP) generates a compiled shape file (SHX).
A complied shape/font file.
Landscape Library. Used with the LSLIB command
Materials library file. Used with the MATLIB command.