"Peter Duniho" wrote in message
...
Sure, that seems like a good example. Possibly the only one. 
I provided two examples.
If the aircraft isn't flying IFR, I don't see how ATC *can* give a
"clearance for the approach". As far as I know, there's no mechanism
under VFR to receive an instrument clearance. I realize that a controller
may offer IFR-like handling to facilitate the practice approach, but just
as the approach isn't a real instrument approach, neither is the handling
a real clearance.
Is there some regulation that I'm missing that allows an actual approach
clearance to be granted to an aircraft operating under VFR?
ATC provides separation between IFR aircraft and VFR aircraft practicing
instrument approaches wherever it is practical to do so and has been doing
so for a long time. At those locations VFR aircraft are given an approach
clearance. See AIM para. 4-3-21.d.