ICP171I WARNING OS KEYWORD CONVERTED TO CHPARM KEYWORD

Explanation
The OS keyword has been converted to the CHPARM keyword. 
Note: Beginning
with ICP IOCP 2.1.0, the OS keyword is disallowed.

System action
IOCP prints this warning message following the CHPID statement
in question and continues processing.

Programmer response
Change all OS keywords to the CHPARM keyword.