The NFL banned flamethrowers during games after an incident where one caused a fire in a stadium.
The NFL banned certain jersey designs, known as Color Rush uniforms, after colorblind fans complained they couldn't differentiate between teams.
The NFL banned certain player celebrations that were deemed offensive, excessive, or directed at opponents.
The popular NFL video game, Madden, has its own set of bans, including customizing team logos and player equipment.
Cheating has been a part of the NFL, with players using illegal substances to gain an advantage.