"This document contains information about cancel messages on Usenet, such as who is allowed to use them, how they operate, what to do if your message is cancelled, and the like. It does not contain detailed instructions on how to cancel a third party's posts. It is not intended to be a fully technical document; its audience is the average Usenet user, up to a mid-level administrator." (First paragraph of the FAQ)
The Spam Thresholds FAQ, Current Usenet spam thresholds and guidelines, by Chris Lewis and Tim Skirvin
The Bincancel mini-FAQ and The Bincancel FAQ, full version. Both are maintained by Shaun Davis-Gluyas (A bincancel is a cancel for binary messages posted to a non-binary newsgroup.)
"This FAQ answers questions about bincancels that have been frequently asked and frequently answered on news.admin.net-abuse.misc and .usenet. Many of the answers here are from various posts made to those two newsgroups during 1996, not from some coffee meeting somewhere." (First paragraph of the FAQ)
The Newsgroup Care Cancel Cookbook, maintained by Rosalind Hengeveld, maintainer of the NoCeM Registry, "merely takes up where other FAQs leave off: how to 'write your own cancelbot' with nothing more than your home pc and common software, only thorough understanding of what can and what cannot be canceled."
Ed Falk's Spam Tracking Page with up-to-date netnews spam statistics by source, the "Spammer Quick Reference", and latest spam news, among other informative pages.
The Cancelmoose[tm] Home Page (NoCeM)