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

ASCII or EBCDIC

The DEFAULT(ASCII) option indicates that, by default, character data is held in native Intel style. When you specify the EBCDIC suboption, the compiler must generate extra instructions for most operations involving the input or output of character variables.

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