Many years ago I noticed my Skipper's Fireblade in the yards with an unusual set of tyres on it. "oh yes, I'm just scrubbing them in for a track day at Brands tomorrow." Tomorrow came & went and the following day there was some debate in the yard as to whether they were still legal.
The most interesting feature was that there was absolutely no chicken strip whatsoever; just a row of little puckered rubber balls around the very outside edge. Hands down the best rider I've ever met, I tried following him once and never made that mistake again.