In the CMOD V8.4.1 (yes, V8.4.1) readme was an optional step to run arssyscr.
This switched the CMOD system log to using the new date/time format (much more granular).
It also increased the size of the MSG_TEXT field to 2,000 chars.
Now, years later, we're running into S0C4's in ARSRPT from shops who haven't updated their system log yet.
This is due to a truncated file from an ARSDOC QUERY which ARSRPT uses behind the scenes, because of the smaller MSG_TEXT field.
Ed