Warning

The Bottom section is one of the four main sections of the xkcd.com website.

The warning on xkcd served as a humorous advisory message to users about the contents of the comics. It was originally added to xkcd.com before April 8th, 2006, but it was removed on September 12th, 2016 after almost a decade. It used to appear between Randall's list of "Comics I Enjoy" and the footnote. It stated:

Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).

Removal of the warning

On September 12, 2016, the comic 1732: Earth Temperature Timeline was published and garnered attention from a much wider audience compared to other xkcd comics. Four hours after its release, the warning, along with the previous footnote, were both removed from the site. While a new footnote was added 22 days later, the warning never came back. This new footnote did not include a reinstatement of the original warning message. The removal of the warning and the footnote was likely a result of the comic's sudden surge in popularity, to ensure that new fans were not deterred by the messages.