According to the SAP documentation:
System functions are only intended for internal usage. Incompatible changes and further development is possible at any time and without warning
So calling system C functions using a
CALL statement should be avoided.
Noncompliant Code Example
CALL 'MULTIPLY' ID 'P1' FIELD '9999'
ID 'P2' FIELD '9999'
ID 'RES' FIELD RESULT.