The DFLTUSER system initialization parameter specifies the RACF® userid of the default user; that is, the user whose security attributes are used to protect CICS® resources in the absence of other, more specific, user identification.

For example, except in the case of terminals defined with preset security, the security attributes of the default user are assigned to terminal users who do not sign on.

The specified userid must be defined to RACF if you are using external security (that is, you have specified the system initialization parameter SEC=YES).

The specified userid is signed on during CICS initialization. If it cannot be signed on, CICS fails to initialize.

Restrictions You can specify the DFLTUSER parameter in the SIT, PARM, or SYSIN only.