It shall be and is hereby made unlawful for any person to wilfully destroy, mutilate, remove or alter the serial number or other number stamped on any bicycle frame licensed pursuant to the provisions of this chapter. It shall be unlawful for any person to remove, destroy, mutilate or alter any license sticker during the time in which such license sticker is in effect. (Ord. 490, 8-7-1941; amd. 1987 Code)