How to cancel an article you have posted

Eventually, it will happen to you. You have posted an article and then realized that you have committed a horrendous faux pas. Or there is a stupid typo or misspelled word. Or you just plain goofed up a crucial fact. Or you have advertised something for sale and sold it almost immediately, and your mailbox is still filling up with offers.
Most newsreader programs allow you to send cancel messages regarding articles that you have written. In theory, a cancel should delete the original article from your own news server. It should also propagate to other news servers, asking them to delete it as well, which they should.
== Supersession ==
The news protocol also allows an article to supersede an earlier version of the same article; the superseding article should remove the previous one. This mechanism has many of the same strengths and weaknesses cancels have.
== Why a cancel message might fail ==
Sending a cancel message is usually easy. This page includes detailed instructions for a selection of newsreaders. However, you can no longer rely on a cancel actually to remove your article from a newsgroup. Here are a few reasons why.
=== Vandalism ===
Nowadays, cancel messages are highly abused. Because cancels are easy to falsify, and because vandals often send huge amounts of forged cancels, it is becoming less and less common for news servers to act on cancel messages.
==== Vigilantism ====
Even if a cancel initially is successful, there are resurrection robots that may repost the original article (on the assumption that the cancel was illegitimate).
=== Propagation outside newsgroups ===
Netnews articles are exchanged between news servers, but they may also be gatewayed automatically to mailing lists and web-based archives. Additionally, they may have been quoted manually somewhere. Such media often do not (or even, by design, cannot) honour cancels.
=== Usability issues ===
==== Article expiration ====
Most newsreaders allow you to cancel an article only while the article has not yet expired on your news server. If the article has already expired from your server so that you no longer can call it up and read it again, you are probably out of luck.
You could compose and inject your cancel message manually. Although the protocol specification explains how, that task may be rather difficult for someone who is new to newsgroups.
==== Email address settings ====
If you follow the instructions, but get an error message that says something like You can't cancel someone else's article, your newsreader was not installed properly. Complain to your system administrator about it, if he/she installed your newsreader. If you installed it, check your documentation and make sure that your newsreader and news server software agree on what your email address on the From: line should be.
If you were trying to cancel someone else's article, please be aware that falsifying cancel messages is a severe breach of netiquette.
== How to send a cancel message — instructions by newsreader ==
=== Gnus (under Emacs) ===
# Select the article and start reading it.
# Press C (capital) to cancel it (function `gnus-summary-cancel-article')
Thanks to Nat Makarevitch (nat at nataa.frmug.fr.net), 8 October 1995.
=== Netscape (Macintosh, Windows) ===
Netscape versions prior to 2.0 cannot cancel articles.
In version 2.0, use the Cancel command in the Edit menu. (I think I recall that a similar command is available in newer versions as well.)
=== NewsWatcher (Macintosh) ===
These instructions are for version 2.0b27. Other versions may vary.
Select the Cancel Article command from the Special menu. This can be done while the article is being read or while it is selected in the author/subject window.
Thanks to an anonymous contributor, 6 January 1996.
=== nn (UNIX) ===
# Select the article and start reading it.
# Press C (capital) to cancel it.
Thanks to Wolfgang Schelongowski (spamtrap at xivic.prima.de), 30 September 1995.
=== pine (UNIX, DOS) ===
pine does not have a built-in cancel feature.
However, it is possible to cancel articles by manually creating the necessary header lines. Detailed instructions can be found in Nancy McGough’s news article , which is available at least through Google Groups.
Thanks to Gotfryd Smolik, 29 May 2008.
=== rn, trn (UNIX) ===
# Select the article and start reading it. In order to show articles you have already viewed, you will probably have to use the U (capital) command while looking at the thread selector,
# While you are reading the article — or at its end — press C (capital) to cancel it.
If you want to post a corrected version of the article, press Z instead. Then you can edit the article, and trn will post it in such a way that it simultaneously cancels the old version. The contributor is unsure as to whether this also works in rn.
=== slrn (UNIX, VMS) ===
# In article mode, select the article that is to be cancelled.
# Press Esc, then Ctrl-C.
Thanks to John E. Davis (davis at space.mit.edu), 3 October 1995.
=== Tin (UNIX) ===
While viewing the article text (you may have to use r to toggle read/unread articles), just press D (must be capital).
Thanks to an anonymous contributor, 8 October 1995.
=== Turnpike (Windows) ===
# Select the article in the newsgroup. If it has not yet appeared, locate it in a mailroom view (File/New maillist/Mailroom).
# Select Cancel article from the article menu. A new window, containing the details of the message to be cancelled, will appear.
# You should edit the body text of the message to indicate why the message is being cancelled. This is not strictly necessary, but it is polite since at some sites, humans will look at the cancels.
# Press Post, go online and send the cancel.
Of course, you can only cancel your own messages. The article you are cancelling must be in the newsgroup on your computer, or in the record of outgoing articles.
Thanks to Richard Clayton (richard at turnpike.com), 19 September 1995.
=== WinVN (Windows. Versions above 0.99.4) ===
# In the group list window, open the article.
# In the article text window, select File/Cancel article.
You may edit the text of the cancel article. This is only possible on articles you have written.
Thanks to Christian Perrier (bubulle at bubhome.frmug.fr.net), 4 October 1995.
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This article is based on material authored by members of the Moderation Board and nnq-workers mailing list, particularly by Jon Bell (until 2005) and Thor Kottelin (since 2007).
Category:news.newusers.questions