Usenet Newsgroup Terms - Cancel-Message
Cancel-Message - A control message that requests for a Usenet server to delete a certain article. Only the administrator of the service or the author of the message is allowed to request a cancel-message. This created a solution where someone would be able to take back their words or remove information that was either inaccurate or no longer needed within particular Usenet newsgroups. Since its inception, other uses have been found. Primarily, the control of spew or spam on Usenet newsgroups. Cancel messages are sent out as a standard usenet newsgroup post and are defined as "Control:cancel" in the header. If a system (i.e. newsreader) accepts cancels, the post with the header is deleted from the system and the general list of headers. The most popular reasons fall under:
ECP cancels (Excessive Cross Posting)
Binaries in a non-binary group
Forgeries in the user's name.