What is the "System Message" on the email output of a process

Hi,

I am sending an email out to many users when a particular process errors.

We get the email but the below is showing:

Process Instance:           3417356

Process Name:               ISCFPCRD

Process Type:               SQR Report

System Message:

The PeopleSoft Technical team will look at the issue and
contact accounting with the appropriate details.

My users have asked me to fill in the "System Message" and I have tried using a custom message and a message catalog entry and the field is always blank.

Any help would be greatly appreciated,

Susan