Definition: DOS startup options
Starting with DOS 6, there were multiple startup options for the CONFIG.SYS and AUTOEXEC.BAT files. The user could bypass them, decide which lines to execute or set up multiple configurations for selection at startup.
Both the CONFIG.SYS and AUTOEXEC.BAT configuration files could be bypassed for a "clean boot." To troubleshoot a new driver or TSR, CONFIG.SYS commands could be executed a line at a time to see which one caused a problem. Multiple configurations were valuable when memory was limited in early computers, and a laptop on the road needed fewer drivers than it did when plugged in at the office.