Yes thats correct. Been the case for a good many years now. I've heard about someone at Manc, think they must surely be the last one floating around on the old contract. These days its crap pay whilst training at college, crap pay whilst training at unit, if valid before the 3rd anniversary of joining then you go on to slightly less crap pay, until the 3rd anni, at which time you join the main pay scale. If valid after then you go straight onto main scale, no back pay. Which is how it should have always been. Your no use till your valid.