From - AutoDesk
Complex linetypes are custom linetypes that can contain embedded shapes or text. Before you create complex linetypes using text, consider how the font settings, scaling, and colors will affect the linetype.
Text style settings
The text height setting will affect the linetype if it is set to a specific height other than zero (0). No other text style settings will apply, unless multiline text is placed in the drawing using the same text style defined in the complex linetype. You must use the REGEN command to see the changes.
Note: Use a text editor such as Notepad to create the complex linetype. If you try to create the linetype within the program, the following error message is displayed:
INVALID number or bad continuation
Before you create a linetype with text in it, define the text style that you will use. Unless the text style used in the linetype has been defined in the current drawing, the following error message (or similar) is displayed when you try to load the line:
Bad definition of (linetype name) at line (line#) of file c:\Acltwin\filename.lin
Note: You will also receive this message if there is not a hard return, or <enter>, placed at the end of the file that you have created.
If you plan to use the LTSCALE or CELTSCALE command in the drawing, the text will change to the new size. Unless you follow these rules, it will shift out of alignment with the dashes that you have created.
The following exercise will demonstrate how to create a complex linetype and change the scale proportionally.
When you create the complex linetype, you will assign the actual text height for the "S" transform. The linetype transform values S= (text height) and Y= (Y offset) are for centering the characters. If the S=1, then you will want to offset Y=.5 to center the line.
Tip: You may want to place a line of text with mtext first and use the distance command to check the character height. Some fonts adhere to standards which may cause the center to be off.
Now try CELTSCALE set to 2 and place a new line on the screen.
The dashes stay in proportion to the text and everything will scale together.
A closer look at the linetype will tell what each part means. Each item is separated by commas.
*MAP,--- Map ---
The complex linetype must be only one color. It can be set to color bylayer or to any color using Entity Creation mode. The text is part of the line and not a separate entity. A complex line cannot be exploded.
Compiled shape files (SHX files) can be used in complex linetypes. These SHP and SHX files must be created in the full version of AutoCAD. The location of the SHX file must be set in the support path. Use the instructions in the AutoCAD Customization Guideunder "Linetype Definition Files."
An AutoCAD drawing that contains such a linetype must be accompanied by the compiled shape file or SHX file where the shape is defined, as well as the LIN file where the linetype is defined.
Tip: For more information about complex linetypes refer to Help.