When JES2 is started, it uses the specified start options to determine how it will perform the current initialization. The start options described in this section are defined by JES2. However, you can define other start options for your installation by using the scanning facility (a $SCAN table is provided for initialization options) or an Exit 0 routine for this purpose. (See z/OS JES2 Installation Exits, SA32-0995 for more information about these procedures.) Unless these options are specified in the JCL procedure that is used for automatic starting of JES2, you must specify the start options from the console.