The call stack is the ordered list of all programs or procedures currently running for a job. The programs and procedures can be started explicitly with the CALL instruction, or implicitly from some other event.
The call stack is available at both the job level and the thread level. On the character-based interface, the call stack is a last-in-first-out (LIFO) list of call stack entries, one entry for each called procedure or program. In iSeries Navigator, by default, the last entry in the stack appears at the top of the list. However, the ordering can be changed by using the Sort ascending or Sort descending buttons.
The information that is included in the Call Stack display includes the invocation information for the original program model (OPM), integrated language environment (ILE), i5/OS Portable Application Solutions Environment (PASE), and Java applications. Also, if you are running under a user profile with *SERVICE special authority, you will be able to see additional entries for licensed internal code (LIC) and i5/OS PASE Kernel.