The number 69 is not explicitly banned by written rule in the National Basketball Association rulebook, but players are effectively prohibited from wearing it due to traditional league numbering conventions and standard digit restrictions. The NBA generally restricts player jersey numbers to single or double digits between 0 and 55 to ensure officials can easily signal fouls using standard hand gestures (which utilize digits 1 through 5). Consequently, unconventional numbers like 69 are not issued to players.