Referee (ice hockey)

In ice hockey, an official is a person who has some responsibility in enforcing the rules and maintaining the order of the game. There are two categories of officials, on-ice officials, who are the referees and linesmen that enforce the rules during game play, and off-ice officials, who have an administrative role rather than an enforcement role.

As the name implies, on-ice officials do their job on the hockey rink. They are traditionally clad in a black hockey helmet, black trousers, and a black-and-white striped shirt. They wear standard hockey skates and carry a finger whistle, which they use to stop play. They communicate with players, coaches, off-ice officials, both verbally and via hand signals. Starting in 1955 with the introduction of the black-and-white jersey, NHL on-ice officials wore numbers on their back for identification. In 1977, NHL officials removed the number and had their surnames on the back of their jerseys for identification, normally in a single row across the shoulders. (Some officials with long names would have their name in two rows, the most notable example being Andy Van Hellemond.) Starting in 1994, however, NHL officials returned to wearing numbers on their shirts, a procedure adopted by other leagues.

In the early days of hockey when the NHL was born (1916), the referees would be clad in a vest and tie along with their pants and carry a bell, not a whistle, to stop the game in progress. In those days, penalties were assessed more on common sense rather than following strict rules, and the official would deem what was allowed and not, as well as the length of the penalties.

Later, NHL referees wore cream-colored sweaters over a shirt and tie, from the 1930s to the early 1950s. They then briefly wore orange sweaters with half-zip fronts (and without neckties), until the black-and-white-striped jersey was introduced in 1955.

A referee is responsible for the general supervision of the game and (s)he can be identified by his/her red or orange armbands. Under most officiating systems, (s)he is the only official with the authority to assess penalties for violations of the rules. However, the linesmen can report a variety of penalties, such as "too many players" and major penalties, to the referee, who may then assess the penalty. The referee also conducts the opening face-off in each period and face-offs that follow after a goal is scored, which are done at the center ice face-off dot.

...
Wikipedia