RSTRCT_INCL_NULL (System Preference)#
The preference, RSTRCT_INCL_NULL, is used to control whether null values are included when a 'Restrict To' Security Value is defined on IMSV.
Default value is 'N' (no/false) which implies that records with null values in 'Restrict To' secured columns will not be visible to the user.
NOTE: if this preference is enabled, all 'Restrict To' security values will be affected.
The preference may be defined by site in (IMST) or by role in (IMRO).