I have a bunch of show flyers (old and recent) that would be cool to upload. They often have unique art compared to the poster

With that in mind, in some cases the flyer is the poster/the only thing that is printed. I think in those cases it should be marked as poster + flyer (so we can display the art in the sidebar). Flyer-only seems to have been the case for most punk/metal shows in Japan.

"Flyers thinking here more about the rave scene, flyers were often the main way that raves (legal or otherwise) were advertised; there is a big scene in collecting and preserving these flyers and they can be just as interesting as posters IMO."
- sound.and.vision