it's not an w3c-standard to be blacklisted.
Some companies do it, for example an ISP if your PC is used by a botnet or an e-mail provider if your PC is used to send massive spam. In that case, the first thing to do is ask "why adid you blacklist me", the second thing is erase the cause, and the third to convince the organisation that put you on the blacklist that you're clean again and did take preventive measures to prevent it from happening again.
But in your case, it might just as well be something totally different.
Have you ever experienced the nightmare of having your IP address blacklisted? How did you get it resolved? Did it take long? How did you find out which blacklist you were on? Any advice on IP blacklist prevention?