On this EF lens nothing apart from a shade flange by the electronic contacts protrudes past the plane of the rear of the lens mount bayonet. Click on previous to see the different mount arrangement of the 18-55mm EF-S lens. Note also the white dot at the edge of the lens mount at one o'clock. That is the target alignment mark for mounting the EF-S lens instead of the normal red mark at 12 o'clock on the mount itself. It's possible to force the EF-S lens onto an EOS camera not designed to take it, but it' designed not to feel right if you attempt it.
