MLP-- you just type it up like: Blacklist: *name*, *name* etc
it's just a list, that you can put either on your profile or gallery presentation

how do you make it to work?

Pretty much what has already been said, but someone can also be listed on a black list if that person is a noob, or colors linearts poorly.

A blacklist is a list of people who are mean or something, and usually, people have one on their gallery or their profile. People who DON'T do anything bad or are friends with you is your white list. If a person who is on your blacklist has a good explanation, you can take them off the list.

Well a somebody gets put on a blacklist for being bad ( art theft, being mean etc) and they are not to use grafics or bases of yours. I hope that helps^^