The league implemented the new rule in late March. Under the new directive, it is a foul if a player lowers his head to initiate and make contact with the helmet on an opponent.

It’s happened to many football fans. Your favorite NFL team blocks an explosive, downfield pass. But then a flag is thrown. Your excitement turns to anger. It’s pass interference. Pass ...

b. Physical interference with an official is a foul charged to the team for unsportsmanlike conduct. (A.R. 9-2-5-I)." ...