tomason can be grouped by features they have in common. these include: "useless stairways", "pointless doorways", "overhangs", "blocked windows", "sealed up walls", "a-bomb type", (doors opening from a high place into open air), "outies", "poundcakes", "atago" (strange bumps or things sticking up out of the road for no reason), "premature burial" (when a wall is built partly covering an existing feature), and more.