ShyTorque, I may have missed the point of your response, but ATC and the radar have no way of knowing what pressure setting the unverified 2400 traffic is on. It would make sense that it is either local QNH, RPS or 1013, but who knows.
I don't like the indicating above/below, and will always say "indicating xxxx unverified."
Widger: I read
.......but if you are providing a radar service across a number of ASRs then 1013 is better
as '...providing a radar service for a number of ARS*S....', but that is probably more to do with the day I have had!