USA Hockey has done some rule changes over the spring/summer:
USA Hockey Junior Tier I & Tier II Rule 614 fighting
USA Hockey Junior Tier III Rule 614 Fighting
For Tier I & Tier II: A major penalty plus a misconduct penalty shall be assessed to any player who engages in fighting. A minor, double minor or major penalty plus a misconduct penalty, at the discretion of the Referee, shall be assessed to any player who, having been struck, continues the altercation by retaliating.
For Tier III: (a) A major penalty plus a game ejection penalty shall be assessed to any player who engages in fighting. A minor, double minor or major penalty plus a game ejection penalty, at the discretion of the Referee, shall be assessed to any player who, having been struck, continues the altercation by retaliating.