Use this command while the debugger is silently running in the background (via the Debug -> Run command). This allows you to pause (but not abort) the script at any time. The debugger will kick in and pause at the instruction that was executing when you issued the Break. You can then use the Step commands to step through instructions, or use the Debugger Window's Command box to enter REXX instructions on-the-fly, or resume running the debugger silently.