Usenet spammers have alleged that cancelbots are a tool of the mythical Usenet cabal.
Pseudosites are referenced in cancel headers by legitimate cancelbots to identify the criteria on which a message is being canceled, allowing administrators of Usenet sites to determine via standard "aliasing" mechanisms which criteria that they will accept third-party cancels for.
Currently, the generally accepted criteria (and associated pseudosites) are:
|Breidbart Index above the cancel threshold for the group or hierarchy||cyberspam!usenet|
|"Make money fast" schemes||mmfcancel!cyberspam!usenet|
|"Spew" (large number of nonsense or repeated postings)||spewcancel!cyberspam!usenet|
|Binary files posted to a group that doesn't allow them||bincancel!cyberspam!usenet|
|Retromoderation (only applies to groups that have a retromoderation policy in place)||retromod!cyberspam!usenet|
|Ad cancels within the biz.* hierarchy||adcancel!cyberspam!usenet|
|Messages originating from sites or networks under active Usenet Death Penalty (UDP) sanction by the community; the UDP is exceedingly rare, requiring a broad consensus that a Usenet site is acting in a manner generally harmful to the community, and active cancellation under a UDP is even rarer still||sitenameudp!udpcancel!cyberspam!usenet|
By general convention, special values are given in X-Canceled-By, Message-Id and Path headers when performing third-party cancels. This allows administrators to decide which reasons for third-party cancellation are acceptable for their site: