Symbolic constants

In IBM® Enterprise COBOL Version 4 Release 2 Performance Tuning, it says: "If you want the optimizer to recognize a data item as a constant throughout the program, initialize it with a VALUE clause and don't modify it anywhere in the program".

This remains a valid and important recommendation, with one difference. The V6 compiler tolerates the data item being reinitialized to an identical value as was specified in the VALUE clause. In this case, the compiler recognizes that the value of the data item has not changed from its initial value and will still treat it as a constant.