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 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.
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.
Although the rules do not specify any other distinction between the captain and his teammates, the captain has numerous responsibilities to the team, particularly in North American professional hockey. The captain is a dressing room leader, and also represents the players' concerns to management.
The captain is often considered the primary representative of the team to the public, and sometimes is responsible for organizing the team's social functions and performing ceremonial on-ice functions, such as award presentations or ceremonial faceoffs.
NHL teams need not designate the same player as captain from game to game, though most teams do. For instance, in the 1985–86, when Boston Bruins captain Terry O'Reilly retired, Ray Bourque and Rick Middleton were named as co-captains of the team. Middleton wore the "C" during home games and Bourque for road games during the season's first half, and the two switched for the second half. This arrangement continued until Middleton retired in 1988 and Bourque became the sole captain. Some teams name two (such as the Buffalo Sabres during the 2005–06 and 2006–07 NHL seasons) or three (such as the Vancouver Canucks during the 1990–91 season) captains for a season. Some teams rotate captains rather than keep one for an extended period of time (the Minnesota Wild rotated captaincy every one or two months until the 2009–10 season, when Mikko Koivu was named the first permanent captain since the franchise's inception). During each NHL game, however, only one player can officially be designated as captain.