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

Regional data sets

A description of regional data sets and how you can use them is presented in Defining and using regional data sets.

Note:
Regional in this context means the same thing as REGIONAL(1) does in PL/I for z/OS.
Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide