Defining SMS as trusted to RACF generally allows the SMS address space to bypass RACF authorization checking and so access the SMS configuration data sets.
Regardless of what release level your system is running, assigning the TRUSTED attribute to the SMS address space is required, because SMS accesses a variety of unpredictably named data sets, in particular the SMS configuration data sets. SMS also supports some automatic functions to maintain the SMS configuration data sets with the appropriate attributes to aid in accessing the SMS configuration data sets more efficiently. For example, when SMS determines that the REUSE option is not specified when the CDS is activated, SMS automatically attempts to alter the CDS to have the REUSE option.
For details about defining SMS as trusted to RACF, refer to the topic about associating started procedures and jobs in z/OS Security Server RACF System Programmer's Guide, and the topic about using started procedures in z/OS Security Server RACF Security Administrator's Guide.