Developer for System z Enterprise COBOL for z/OS, Version 4.1, Compiler and Runtime Migration Guide
Corrective action for variable-length group moves:
You can take the following steps:
See if any of your COBOL programs have the variable-length data movement
statements by compiling them with the CMPR2 and FLAGMIG compiler options.
This completion will flag all variable-length group moves with receivers that
contain their own ODO objects and are not complex ODO items.
See if any data that was previously left unchanged and is now being set
to blanks is referenced after the data movement statements. In the example,
if the ODO object has a value of 5 and a maximum value of 10 and the code
uses data in occurrence numbers 6 through 10 after the MOVE, then the program
will have different results between CMPR2 and NOCMPR2.
Change the receiver in the data movement statement to use reference modification
to specify explicitly the length of the receiving field. For example:
MOVE ODO-SENDER TO ODO-RECEIVER (1:LENGTH OF ODO-RECEIVER).