DNS Blacklists and Whitelists

The rise of spam and other anti-social behavior on the Internet has led to the creation of shared blacklists and whitelists of IP addresses or domains. The DNS has become the de-facto standard method of distributing these blacklists and whitelists. This memo documents the structure and usage of DNS-based blacklists and whitelists, and the protocol used to query them. This document is not an Internet Standards Track specification; it is published for informational purposes.