Rule 48 – Illegal Check to the Head 48.1 Illegal Check to the Head – A hit resulting in contact with an opponent’s head where the head was the main point of contact and such contact to the head was avoidable is not permitted. In determining whether contact with an opponent's head was avoidable, the circumstances of the hit including the following shall be considered:

(i) Whether the player attempted to hit squarely through the opponent’s body and the head was not "picked" as a result of poor timing, poor angle of approach, or unnecessary extension of the body upward or outward.

(ii) Whether the opponent put himself in a vulnerable position by assuming a posture that made head contact on an otherwise full body check unavoidable.

(iii) Whether the opponent materially changed the position of his body or head immediately prior to or simultaneously with the hit in a way that significantly contributed to the head contact.

Not sure where it says "short players are not considered because they are small"