Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

CDECL linkage

To use this linkage convention, you must specify the OPTIONS(LINKAGE(CDECL)) attribute in the declaration of the function, or specify the DEFAULT(LINKAGE(CDECL)) compile-time option.

Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide