TheSECUREcommand protects programs lines so they cannot be listed. Secured lines are listed as a line number followed by an asterisk "*" character. If no program lines are specified, all program lines are secured. If no end-line is specified, only the start-line is secured.
Warning:Once a line has been secured it can not be un-secured! Make sure that you have another copy of the program before you use theSECUREcommand.