The wiki for Menu board seems to be what is more specifically a Sandwich board, but it seems to be used as a catch-all tag for any surface with menus.
Looking at menu however, this seems to be more specifically paper menu, but it also says:
For menu written on other surfaces, see price list.
Which theoretically should be all the other posts that aren't specifically a sandwich board but instead it apparently nothing to do with food and is instead a wholly sex-related tag.