In this article, we will only discuss community guidelines violations. Information on copyright infringement is available in another article.
What can't be posted?
Spam and fraud. Bots for getting views, likes, comments, clicking ads, impersonating another person, placing links to prohibited content on the channel, etc.
Sensitive content. Violence, sexually explicit material, self-harm, and anything else you wouldn't show your mom.
Acts of cruelty. Harassment, discrimination, bullying, crime, etc.
Illegal goods. Weapons, drugs, organs and everything else that you can hear about in "Law and order".
The full list is here.
If you violate the YouTube community guidelines, you may face 3 levels of problems:
Level 1 - deleting the video
This is something YouTube can do if you violate someone's privacy. Other than deleting the video, there are no consequences for you.
Level 2 - deleting the video with a notification.
Notification (not to be confused with a warning!) is a "zero strike" that you get once and for all if you break the rules of YouTube. The notification does not affect the channel's operation in any way, but it is not removed.
Level 3 - deleting the video with a stike.
Strike is issued if the community guidelines are violated again. It temporarily restricts the channel. For example, for a couple of weeks it will be impossible to do live streams, upload new videos, make playlists, etc. The strike is removed from the channel in 90 days. 3 strikes on the channel in 90 days results in the deletion of the channel. So be careful with that.
All these 3 problems will be with you if the violation really happened. If you did not violate anything, be sure to appeal these decisions:
If you mistakenly received a strike, DO NOT DELETE THE VIDEO. If you delete the video from your side, there is no way to remove the strike.