Rule 50. Boarding and Body Checking

(a) A Minor penalty or, at the discretion of the Referee, a Major penalty and a Game Misconduct penalty, based upon the degree of violence of the impact with the boards, shall be assessed any player who body checks, cross-checks, elbows, charges or trips an opponent in such a manner that causes the opponent to be thrown violently into the boards. If a player is injured a Major penalty and a Game Misconduct penalty must be assessed.

(b) A Minor penalty or, at the discretion of the Referee, a Major penalty and a Game Misconduct penalty shall be assessed any player who, in the opinion of the Referee, intentionally body checks, bumps, shoves or pushes any opposing player. If a player is injured, a Major penalty and a Game Misconduct penalty must be assessed. When the offensive player is running towards the defensive player, the defending player may not hit the offensive player by going in the opposite direction to that player. The body contact must be as a result of the movement of the offensive player. There must be no action where the offensive player is pushed, checked or shoved into the boards. Where, in the opinion of the Referee, accidental contact has taken place, no penalty shall be assessed. 

SITUATION 1 Rule 50 (b)
The situation of a player steering or directing an opposing player into the boards, without actually touching them, is acceptable. The most obvious example of this may be seen when a player is coming down the floor with the ball and they have to make a move or play on the defensemen. Quite often the ball carrier will try to go wide along the boards. In this case, we say that the defenseman has the right to close off the boards, in order to force the ball carrier to slow down or towards the middle of the floor. The principle that must prevail is that no player is entitled to use their body to intentionally body check, bump, push, or shove an opponent.