Use the OPTsdef statement to display or override various JES2 start options. Most of these options can only be overridden when the JES2 initialization process is in CONSOLE mode. The default values for each option are taken from the value specified when JES2 is started (MVS™ START command or JES cataloged procedure EXEC statement). See z/OS JES2 Initialization and Tuning Guide for the default that JES2 uses if the option is not specified when JES2 is started or on the OPTsdef statement.