I've noticed this a lot. To anyone who knows about what's being shown, they know it's wrong. A few examples: -People who cut their wrists in film. They cut the wrong way. I assume this is to avoid teaching people how to do it correctly? -Swords make schwing sounds when being drawn. In real life, they don't make any sound at all (you'd only hear some wind as the sword goes through the air.). -Fur cloaks. They were almost exclusively worn with the fur inwards and the animal's skin outwards, yet are always portrayed the wrong way round. This is movie specific, but the layout of the defenses in the D-Day Sequence of Saving Private Ryan is all wrong, and they even put the boat-stoppers the wrong way round. I don't see how they could have made this blunder unintentionally... Do you have any specific or general examples of stuff like this?