A captain in ice hockey 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 sweater 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.
Teams may designate alternate captains (often erroneously called "assistant captains").
Alternate captains wear the letter "A" on their jerseys in the same manner that team captains wear the "C".
In the NHL, teams may appoint a captain and up to two alternate captains, or they may appoint three alternate captains and no captain.
NHL teams may choose alternate captains from game to game or appoint regular alternate captains for the season.
In North America, alternate captains perform many of the same leadership and team building roles as the captain.
In the 1969–70 season, the Boston Bruins had three alternate captains (Johnny Bucyk, Phil Esposito and Ed Westfall) instead of a captain sporting the "C." However, as Bucyk was the most senior of the alternate captains, he was first one to be presented the Stanley Cup when the team won the championship in 1970 and 1972.