An exhibition could mean anything really. At the lowest end of the scale...Aoki vs Fedor and Mousasi vs Fedor were literally just them playing around. It was a demonstration. Buakaw vs Saenchai was light sparring with footpads. Ali vs Inoki exhibition was a real competition, albeit with fucked up rules. TUF exhibition fights are 100% real. Here's a good example from a recent New year's Eve card in Japan. Retired K1 legend Masato vs Gomi. Masato's kicks and punches look pretty damn hard. Tenshin has promised a KO. I have a feeling like this is going to be a real fight for as long as it lasts. Other exhibitions where people got KO include Jienotsu vs Aoki and Kikuno vs Jienotsu....although they we're advertised as mixed rule fights if I recall correctly.