This humorous spoof of a Wikipedia notability guideline, originally titled Notability (mailboxes), was started in 2021. You may edit the guideline, but please do so at WP:MAILBOX and not on The Signpost.

On Wikipedia, notability is a test used by editors to decide whether a given topic warrants its own article. This notability how-to guide for mailboxes summarizes consensus reached through discussions and reinforced by established practice, and informs decisions on whether an article about a mailbox or mailbox-related topic should be written, merged, deleted, or further developed. For advice about how to write mailbox articles, see Wikipedia:Manual of Style/Mailboxes and Wikipedia:Mailbox article guideline.

For the purposes of this guide, a mailbox (also known as a letter box) is defined as a receptacle for receiving incoming mail at a private residence or business. A mailbox-related article (MRA) is defined as an article related to mailboxes. A non-mailbox-related article (NMRA) is defined variously as either an article not related to mailboxes or an article related to something that is not mailboxes.

This guide is independent from the other subject-specific notability guidelines, such as WP:NMAIL, WP:NPOBOX, WP:NPOSTOFFICE, etc., and is explicitly listed as an alternative to the general notability guideline. It is possible for a mailbox not to be notable under the provisions of this guide but to be notable in some other way under the general notability guideline or one of the other subject-specific notability guidelines. Conversely, failure to meet either the general notability guideline or other subject-specific notability guidelines is irrelevant if a mailbox is notable under this guide.

1. A non-cool mailbox is presumed notable when it has received significant coverage in reliable sources that are independent of the mailbox or its owner.
2. A cool mailbox is presumed notable when it has received significant coverage in reliable sources that are independent of the mailbox or its owner.
3. A very cool mailbox is presumed notable when it has received significant coverage in reliable sources that are independent of the mailbox or its owner.
4. A mailbox flag is presumed notable when it has received significant coverage in reliable sources that are independent of the mailbox flag, the mailbox to which it is attached, or its mailbox's owner. Mailbox flags which are determined to be non-notable are generally redirected to the page for the mailbox to which they are attached.
5. All carrier pigeons are presumed to be notable.

Some new editors attempt to create a page for their mailbox as their first article, and these are often nominated for deletion. It takes a lot of work to create an article, so if your mailbox article has been nominated for deletion, this may feel very discouraging. But don't panic just yet—deletion isn't automatic; it's a process. While mailbox articles do sometimes get deleted, and authors of non-notable mailbox articles do sometimes get permanently banned from ever editing or reading Wikipedia again and then defenestrated for good measure, this doesn't always happen.

Maybe your initial reaction was feeling hurt, or even angry. Know that plenty of established users have had their mailbox articles nominated for deletion. People will (or at least will try to) argue objectively about whether or not the mailbox is worthy of being in Wikipedia, so try not to take the deletion discussion personally. Listen to the reasons given in the nomination. Address or refute those reasons as best you can (preferably backed with reliable sources, such as the International Journal of Mailbox Studies), and try to improve the article accordingly. Please note that sources that you received via a mailbox cannot be used to support the notability of that mailbox due to the conflict of interest.

• Wikipedia:WikiProject Mailboxes in Red
• Wikipedia:Avoid instruction creep