Notes:

Image explanation (copied from source):

On imageboards, threads have a "bump limit". After so many posts, a thread will stop being bumped and either end up deleted or archived (depending on site/board). After a thread has reached bump limit, there's a window of time where posts can still be made in the thread. If the thread's on a board without an archive, then Laura № 404 can be posted after bump limit but before deletion, reminding posters that they need to wrap up any remaining discussion and go elsewhere.

*Thread Marshal -- Motorsport marshal.
*№ 404 -- If you try to load an expired thread, you'll be taken to a 404 page.
*Laura -- She's dead.
*Chequered Flag -- End of the race.
*End of the World (background) -- End of the Thread.