Slurs in the forums

So, I'm wondering: Where does the line exist for slanderous language. I know people have gotten banned for using "homophobic" language, and for dropping N-bombs, but where does that stop?

As an example;

It would be bannable if someone were called out by using a stereotype concerning skin color.

EDIT: xxxxx used to have specific examples of uncommon, traditionally-less-inflaming ethnic slurs xxxxx


Does this line exist between common, accepted derogatory language (bannable), and words-that-people-use-without-knowing-what-means?

If posting this is against the rules, someone lemme know. :]