Command: MKLTYPE
Select a ".LIN" file: <C:\Express\Drawings\acad.lin>: Enter a linetype file name and directory path
Enter linetype name: Specify a linetype name
Linetype description: Specify a linetype description
Starting point for line definition: Specify a starting point
Ending point for line definition: Specify an ending point
Select objects: Select a line, polyline, lwpolyline, point, shape, and/or text object

A linetype is a repeating series of dashes, dots, shapes, and text objects. With the standard AutoCAD PLINE, LINE, POINT, TEXT, and SHAPE commands, draw an approximation of your linetype; then select the objects at the Select Objects prompt in MKLTYPE.

Usage Example:
Create a dashed cold water linetype.

After specifying the file name, linetype name and description, select points to show the start points and end points for line definition:

Specify the line and text objects to be used to define the linetype:

The linetype is loaded and is ready to use: