This is a special kind of AutoCAD routine from Matt Sibum. It comes inside a file named ACADDOC.LSP, but if you already have a file by this name, do not overwrite your copy. Instead, just append the contents of this file to your existing version. The code itself is designed to change the status bar area of AutoCAD by displaying useful information. It does this by using the Modemacro system variable. After loading the code, the value of certain system variables is shown in the status bar. Feel free to customize the code to your needs, but keep in mind that there is a limited amount of room in the status bar for the output, depending on your screen resolution and other factors.