The NFL was the last of the major professional sports leagues to adopt the third jersey rule in 2002, with the only exceptions being the 1994 season, when teams issued a throwback uniform in honour of the league's 75th Anniversary. Initially, the NFL rule stated that a team may wear their third jersey only once a year, however, after one year this restriction was increased to twice a year. Some teams have exceeded the limit; the 2017 Baltimore Ravens were an example, wearing their all-black uniforms twice that season, and the less-frequent black jerseys on white pants once.