Shortly after the September 11, 2001 attacks, an American flag was added to the shirts of NFL officials, but was removed in 2006.
College football referee Lloyd Olds is credited with the idea after a quarterback mistakenly handed the ball to him.
The original United States Football League, which played from February to July in its three-season existence from 1983 to 1985, allowed officials to wear black shorts for warm-weather games.
In 2010, the UFL switched to a customized version of the traditional black and white stripes, and wore this uniform until its 2012 shutdown.
Although in some states, high school officials wear shirts with two-inch or two and one-quarter inch stripes.
In 2006, the NFL completely redesigned the shirts, going to a sleeker-looking uniform which, however, no longer identified a given official's position from the front.
In 2014, several high school associations started mandating the wearing of the black slacks for varsity level games.
From 1982 to 1986, the D-I Atlantic Coast Conference allowed officials to wear white shorts for hot weather games.
During each play from scrimmage, the referee is positioned behind the offensive team, favoring the right side (if the quarterback is a right-handed passer).
During punts and field goals, the referee observes the kicker (and holder) and any contact made by defenders approaching them.
In college football, the NFL, and other professional leagues, and in some high school games, the referee announces penalties and the jersey numbers of the players committing them (required for college and professional games; high school referees are no longer prohibited from announcing the number of a player committing a foul; on rare occasions, the player's position is announced instead of the jersey number), and clarifies complex and/or unusual rulings over a wireless microphone to both fans and the media.
CFL referees, unlike their counterparts in the NFL and American college football, identify the team committing the foul when announcing penalty enforcement, instead of using "offense" or defense".
In college football, the referee confers with a replay official, who is stationed in the press box above the field, on the play and then announces the final result over the wireless microphone.
During passing plays, umpires move forward towards the line of scrimmage as the play develops to penalize any offensive linemen who move illegally downfield before the pass is thrown or penalize the quarterback for throwing the ball when beyond the original line of scrimmage.
[6] For this reason, the NFL carried out experiments in the 2001 preseason with the umpire placed in the offensive backfield adjacent to the referee.
In 2023 the NFL returned the umpire to the defensive backfield with the side judge for field goal and extra point attempts.
The down judge (DJ) in the NFL, CFL, and the 2022 version of the USFL; head line-judge (H or HL) in college and some states for high school football; or head linesman (H or HL) stands at one end of the line of scrimmage (usually the side opposite the press box, always with the chain crew), looking for possible offsides, encroachment and other fouls before the snap.
As the play develops, the head linesman is responsible for judging the action near that sideline, including whether a player is out of bounds.
Responsibilities on a passing play include watching the receivers near that sideline to a point five to seven yards beyond the line of scrimmage.
The field judge has sometimes been the official timekeeper, and in a number of leagues will run the game clock on a six-person crew.
[18] The position is called the back umpire in Canadian amateur football; all other leagues use the term field judge.
In the 2020 version of the XFL, there is one official dedicated to spotting the ball, with the purpose to reduce downtime during the game.
The primary responsibility for this new position is the action of receivers, and it allowed the NFL to adjust coverage after the umpire was moved to the offensive backfield.
The practice of having the referee announce penalties or clarify complex and/or unusual rulings over a wireless microphone started in the NFL in 1975.
Under NFHS rules used in all states except Texas for high school games, announcing the player's number went from "not allowed" to "not required" in 2014.
(1966 inductee Hugh L. Ray was inducted for his 14-season tenure as the league's head of officiating, an off-field position.)
Advantages to this system include being able to eliminate unqualified officials simply by not offering them a contract the following season.
The level of training and review in which NFL officials participate makes additional time redundant.
The National Football League Referees Association (NFLRA) serves as the union that represents officials in the NFL.
Darin Gantt of Profootballtalk.com and Sam Farmer of the Los Angeles Times lamented that it was in this manner that this gender barrier was broken.