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

content_predefined_reference

This event occurs in element content for the five pre-defined entity references "&", "’", ">", "<" and "’". The parser passes a CHAR(1) or WIDECHAR(1) value that contains one of "&", "'", ">", "<" or '"', respectively.

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