Delayed Offside - Rule 451
Non-whistle arm fully extended above the head. To cancel out a delayed offside, the Linesman shall lower the arm to the side.
Icing the Puck - Rule 460
The back Linesman (or Referee in the Two Official System) signals a possible icing, by fully extending either arm over his head. The arm shall remain raised until the front Linesman or Referee, either blows the whistle to indicate an icing, or until the icing is washed out. Once the icing has been completed, the back Linesman or Referee shall first cross his arms in front of the chest and then shall point to the appropriate face-off spot and skate to it.
Offside Call - Rule 450
The official shall first blow the whistle and then extend the arm horizontally pointing along the blue line with the non-whistle hand.