no spoiler rule
An unwritten rule which involves people telling others NOT to spoil the events which would go on in either a movie, TV show, video game or anything else that entertains a person. It soon became really popular in social media through memes, posts, videos & etc.
It was a no spoiler rule which prompted my refusal to watch"Avengers: Endgame" simply because I feared people would cause problems if I was to break it.