Click on the button to direct MMS to use the macro definition "LIST=1".

 Automatically generated description files will contain the following
 lines:

 .IFDEF LIST
 LST = /LIST
 .ELSE
 LST = /NOLIST
 .ENDIF

 and every compilation command will include the $(LST) macro.

 If this toggle button is clicked on, then every compilation in the build
 will produce a listing file.  If this toggle button is off, no listings will
 be produced.

 Users can use the same mechanism in their own hand-written description
 files.