From the "it's a funny old world" files comes the following story from New York about chess boards. Chess players know the 'white on right rule', but they also know that non chess players will get this wrong 100% of the time. Why this is so is still a mystery, given the laws of probability predict that it should only happen 50% of the time.
In the case of the New York chess boards, not only were the the wrong way round (ie 'black on right') they were boards that were painted onto the tables! Fortunately the error was reported to the relevant authorities, and the mistake quickly rectified.