Good morning, I have been working in COBOL for over 20 years and I have always believed that when a main program (PA) calls a second program (PB) using `CALL PB USING field1 field2 field3` and the procedure in PB is `PROCEDURE USING field1 field2 field3`, the parameters that are put in the `using` procedure of a program (PB) should be defined in the `linkage` section, but I see in the documentation this“ Data-name-1 must be defined as a level 01 or a level 77 entry in the Linkage Section , File Section or Working-Storage Section”
This raises a lot of questions for me.
Has this always been the case? If the variables in PB are defined in the working storage section, what relationship do the variables in PA have with those in PB? How does assigning values to variables in PB affect the variables defined in PA? Could the call be made from PA without passing those parameters?
If data-name-1 is defined as a level 01 or a level 77 entry in the File Section or Working-Storage Section then the activated runtime element operates as if a data item had been declared in the Linkage Section with the same data declaration as data-name-1 and the contents of that data item were moved to data-name-1 prior to executing the first statement in the activated runtime element. In an initial program, these values are overwritten by the initialization of the program's working storage data and are therefore not available to the called program.
