The UGC-136BX seems to be configured to a specific Navy (submarine) workflow.
It seems all received messages are saved into a memory location in the UGC-136B, and the location is printed before the message. If I receive a message (QBF), then I see
MPN 132 A.P.
THE QUICK BROWN FOX
If a delay (mark) of more than 5 seconds occurs, the memory is closed. Upon receipt of the next text, a new memory location is opened
MPN 133 A.P.
THE QUICK BROWN FOX (SECOND LINE)
According to the manual, setting the Norm/Auto Print switch to "Auto print" will prevent the saving to memory but I do not see this (it always adds a MPN XXX).
This is all a little awkward for amateur radio use. The processor is an 8080 clone, so it might be possible to disassemble the code and mitigate some of these annoyances. (although that would be quite daunting)
Michael