The client sees the following messages in their production RMOSTC task:
10.25.01 STC14544 RMOCPT15 Job translation table refreshed
14.30.46 STC14544 *RMOCPP05 WAITING FOR CHECKPOINT
14.45.08 STC14544 *RMOCPP05 WAITING FOR CHECKPOINT
15.23.58 STC14544 *RMOCPP05 WAITING FOR CHECKPOINT
An RMOCPP05 message indicates that there is a temporary spike in activity with the Deliver checkpoint file, which can cause a wait on its availability.
As long as the messages do not repeat frequently, say within 30 seconds, then it is a temporary condition that clears itself quickly.
The message can be issued as well, if the volume where the checkpoint resides is being held by some other application.
The client reported that the messages appear almost daily, sometimes around the same time of day.
It turns out that the system on which this Deliver runs, is "capped" regarding available resources, and that capping of the resources may be what causes the RMOCPP05 message. The messages stopped when the 'long busy' condition is terminated.