rdisp/call_system is a SAP Parameter attribute which is used to control switch on/off CALL 'SYSTEM' information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
The ABAP command CALL 'SYSTEM' can be activated or deactivated using
this switch.
0
CALL 'SYSTEM' deactivated
1
CALL 'SYSTEM' activated
If CALL 'SYSTEM' is deactivated and an ABAP program tries to execute the
ABAP command, an ABAP dump is written.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.