American Football NCAA Approved Ruling 9-1-3
No player shall target and make forcible contact against an opponent with the crown of their helmet. The crown of the helmet is the top segment of the helmet; namely, the circular area defined by a 6-inch radius from the apex (top) of the helmet. This foul requires that there be at least one indicator of targeting (See Note 1 below). When in question, it is a foul.