If you have BTI updates specifying OPT=C as shown in the example below:
The option 'C' is not documented. What is this option used for and why is it not documented.
Release : 11.3, 12.0,12.1
Component : CA-7
OPT=C is an old option and has been replace with OPT=A. If you have OPT=C coded in a BTI job, it will be treated as OPT=A (where option A is for add). This changed was put in CA 7 over 20 years ago and would have been documented at the time of the change.