RFC 5782: DNS Blacklists and Whitelists

The Internet Research Task Force has released a Request for Comments for the Usage of Black 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.