The dress code for the Saratoga Race Course clubhouse.
It seems to me that almost everything at a racetrack is a reaction to the disorder seemingly naturally attached to sports, gambling, and class--the track to contain horses, the racing form to make sense of a confusing array of factors that are supposed to help the gambler choose her horse, and the seating designed to separate classes (even as they inevitably mix). The above photo shows how Saratoga adds fashion requirements to its clubhouse seating.
This could be taken as a type of bigger metaphor for our culture at large (which is the larger argument I'm trying to make). I'm working through sources in architecture, psychology, and sociology in order to help my argument.