Enterprise COBOL for z/OS, Version 4.2, Programming Guide

A called program can directly or indirectly execute its caller.
For example, program X calls program Y, program Y calls program Z, and program Z then calls program X.
This type of call is recursive.

To make a recursive call, you must code the RECURSIVE clause in the PROGRAM-ID paragraph of the recursively called program.
If you try to recursively call a COBOL program that does not have the RECURSIVE clause in the PROGRAM-ID paragraph, a condition is signaled.
If the condition remains unhandled, the run unit will end.