I think the No VTEC whilst cold has been a saftey feature on the R's atleast for a while now, had a mate some years ago who had a DC2 (think it was a DC2 anyway - two round light in front bumper jobbie!), Anyway i do seem to recall he said it won't allow the VTEC to engage whilst it's cold, same with my bosses old ATR too!
Don't think it stops you revving the car as such - just no VTEC as others have said!
If you think the person you were gonna lend the car too was going to mercilesly thrash it though then i'd be firmly in the "no lend" camp too!