Originally Posted by infantrycak
There are several rules which can apply and to more than just head shots. For example, several RBs have been flagged this year for lowering their heads to strike defenders with the crown. There is also a rule a which used to be called for spearing by name but they don't call it anymore although it is still on the books.
Kind of like clipping. It's still on the books, but I haven't seen it called in decades.
EDIT: Since we got on rules, I thought I would mention my displeasure with PI being a spot of the foul call. I would dearly love to see the NFL take the NCAA approach: 15 yds. Those yards should be for offensive or defensive PI. Make it fair on both sides of the ball. End of rant.