VALRET

[RWK at MIT-MC (Robert W. Kerns)]

(VALRET '$$U):VK
$P
;FXPDL OUT OF PHASE (SYSTEM ERROR)
;BKPT WHATEVER

This seems to be a rather humorous bug.  What is going on is that someone
put in code to convert certain VALRET's of strings to suitable things on
other systems, but forgot(!) to put it under an IFE ITS conditional, so
on ITS it tries to convert these things to the apropriate thing, and fails.
The :kill and friends are under the apropriate conditional, but $$U is not.
Thus, it suffers from the embarasement of trying to simulate ITS for ITS, and
doing it wrong.  And even buggily.