Two pairs of parallel lines found on the sides of the faceoff circles located at each end of an NHL rink. During a faceoff, the players positioned to the left and to the right of the players taking the faceoff cannot cross their own hash marks before the puck is dropped, although their skates are allowed to touch the hash marks. Crossing the hash marks results in a faceoff violation.
The players that must respect the ruling about not crossing the hash mark are the players positioned to the left and to the right of their teammate taking the draw, with these players being the left and right wingers in standard five on five situations. When a team has four players on the ice, they usually only have one winger on the ice and may leave one of the positions to the left or to the right of the centreman empty, so only one player must respect the hash mark ruling. When a team is down to three players on the ice and chooses to send out one forward and two defencemen, the defencemen usually position themselves behind the centreman, so no player must worry about the hash mark rule in that situation. All players that must respect the hash mark ruling are allowed to have their stick crossing the hash mark, but no other part of their body must be crossing the hash mark.
Their are 4 faceoff circles on an NHL rink, with each circle having two pairs of hash marks, giving a total of 4 hash marks per circle. Therefore, an NHL rink has 16 hash marks on it.