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

Use of varying strings under DFT(EBCDIC)

If you specify the compile-time option DFT(EBCDIC) and you use a varying string host variable as input to the database, you must initialize the host variable or you might get a protection exception during the execution of your program.

If you use an uninitialized varying string on mainframe DB2, your program would be in error and might also get a protection exception.

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