SIT

The SIT system initialization parameter specifies the suffix, if any, of the system initialization table that you want CICS® to load at the start of initialization.

SIT=xx
If you omit this parameter, CICS loads the unsuffixed table, DFHSIT, which is pregenerated with all the default values. This default SIT (shown in The default system initialization table) is in CICSTS52.CICS.SDFHAUTH, and its source, named DFHSIT$$, is in CICSTS52.CICS.SDFHSAMP.
Restriction: You can specify the system initialization parameter anywhere in PARM or SYSIN, or as the first parameter entry at the CONSOLE.