QAD has a file called custom.i that contains a number of tags that are defined. These tags allow you to customise standard MFG/PRO code, normally by referring to include files or by using things like &IF &ENDIF to block out sections of code.
It is a really powerful tool and makes the MFG/PRO code completely unreadable.
You might find that custom.i contains &GLOBAL DEFINE SOIVRP10-P-TAG38
The new code is then referred to by {&SOIVRP10-P-TAG38} in the code.