Lots of talk about "not above 400 feet".
So just how, standing on the ground, transmitter in hand, looking up at your model, can you assess it's altitude? All very well to say "not above 400 feet", but there is NO WAY to measure this. I challenge anyone to accurately assess the altitude of any aeroplane, full sized or model, simply by looking at it. I know I can't...even RAF runway controllers in their caravans couldn't get it right..and it was their JOB! FPV types with data downlink can have on screen altitude display, but Joe Average with his club Wot-4 just has his eyeballs. Usually the RC types prefer to stay low and close to themselves in any event.