I believe the general rule is to delete the offending post, not to ban someone. I'm sure certain people get escalated because of their previous behavior. Every moderator has said they will delete the post, and that is the warning.
I'm not interested in making a list of rules for people to weasel around. This isn't some game of wheel of fortune. People have common sense, you know what you are saying when you say it. Nivek made his interpretation very clear, if you personally attack someone with racist names he will delete the post. If you repost or do it again, he will ban you for awhile. Seems pretty clear. I have a tendency to delete useless flames and troll posts.
The golden rule would be...."If you make a post, and it disappears.....don't fucking repost it." I could be convinced to add that to the rules.