I've called four delayed knee blocks (aka: illegal chop, aka: hi-lo) this year in seven games - three at high school, one at bantam. I also called one in senior men's ball over the summer, IIRC.
It seems to me that in most cases, coaches are not aware of this rule. The protestation I have heard after calling a delayed knee block in this and previous seasons usually follows the line that "he's allowed to block below the waist, he's a lineman" or some other perception of blocking rules in the close line play area. (I flagged two delayed knee blocks in one game Friday, and the referee informed me the offended bench was screaming about a hi-lo, so clearly, they saw what I did, and knew it was illegal.)
I also wonder if some of us (umpire/referee, in particular) are not aware of this rule (when did it come into effect, anyhow?) or how detect it, because I've also heard the refrain "nobody's ever called that before" from both coaches and, surprisingly, from a veteran official I once worked with.
I'm interested in seeing how many others have seen this infraction, or seen it called. Are coaches aware of this rule? Are players?
Myself, I think some challenges come about because the infraction has an odd name and due to the fact that there's no secondary signal to the infraction. It's just a UR.
Moreover, would it help matters any if we
a) Lobbied to have the name of the penalty changed (to its US equivalent, "illegal chop block" or some such);
b) Lobbied to have a secondary signal, so that it would be UR + chop block (or some such) so as to differentiate it from a block below the waist and thus - maybe - minimize coach confusion?
