(New York, NY) -- The NBA is doing away with "ninja-style headware" this season. The style, which was popularized by the Sixers' Mike Scott and former-76er Jimmy Butler, took off throughout the league, with the Pelicans' Jrue Holiday, the Clippers' Montrezl Harrell, the Timberwolves' Karl-Anthony Towns and the Nets' Jarrett Allen sporting the look. The league doesn't have a formal process to approve headgear, and said they didn't want to interrupt the season last year by intervening. The NBA said teams have raised concerns regarding safety and consistency of size, length and how they are tied.