Click on the button to direct MMS to use the macro definition "DEBUG=1". Automatically generated description files will contain the following lines: .IFDEF DEBUG DBG = /DEBUG DBGOPT = /NOOPTIMIZE/DEBUG .ELSE DBG = /NODEBUG DBGOPT = /OPTIMIZE/NODEBUG .ENDIF and every compilation command will include the $(DBG) or the $(DBGOPT) macro. If this toggle button is clicked on, then every compilation in the build will be compiled with information to be included in the object module for use with the VAX Symbolic Debugger. Also the linker will be directed to generate a debugger symbol table and to give the debugger control when the image is run. Users can use the same mechanism in their own hand-written description files.