Qualifying variables and changing the point of view in COBOL

Qualification is a method of specifying an object through the use of qualifiers, and changing the point of view from one block to another so you can manipulate data not known to the currently executing block. For example, the assignment MOVE 5 TO x; does not appear to be difficult for z/OS® Debugger to process. However, you might have more than one variable named x. You must tell z/OS Debugger which variable x to assign the value of five.

You can use qualification to specify to what compile unit or block a particular variable belongs. When z/OS Debugger is invoked, there is a default qualification established for the currently executing block; it is implicitly qualified. Thus, you must explicitly qualify your references to all statement numbers and variable names in any other block. It is necessary to do this when you are testing a compile unit that calls one or more blocks or compile units. You might need to specify what block contains a particular statement number or variable name when issuing commands.