In ice hockey the captain is the player designated by his team as the only person authorized to speak with the game officials regarding rule interpretations when he is on the ice. At most levels of play each team must designate one captain and a number of alternate captains (usually two) who speak to the officials when the captain is on the bench. The captain wears a "C" on his jersey, while the alternate captains wear an "A".
Officially the captain has no other responsibility or authority, although he may, depending on the league or individual team, have various informal duties, such as participation in pre-game ceremonies or other events outside the game. As with most team sports that designate captains, the captain is usually a well-respected player and a de facto team leader.
According to International Ice Hockey Federation (IIHF) and National Hockey League (NHL) rules, the only player allowed to speak with referees about rule interpretations is the captain, or, if the captain is not on the ice, an alternate captain.