Click on the button to direct MMS to use the macro definition "DIAG=1". Automatically generated description files will contain the following lines: .IFDEF DIAG DIA = /DIAGNOSTICS .ELSE DIA = /NODIAGNOSTICS .ENDIF and every compilation command will include the $(DIA) macro. If this toggle button is clicked on, then every compilation in the build will produce an diagnostics file. If diagnostics files are produced during a build, and LSE is running, the user is able to do a REVIEW of each compilation from MMS. If this toggle button is off, no diagnostics files will be produced. Users can use the same mechanism in their own hand-written description files.