There's a poster for Monsieur Hulot's Holiday (1953) in Lisa's room. It says "Les Vacances de Mr. Hulot" instead of "Les Vacances de M. Hulot."
Bart returns to the shelf a bottle of "Whiskey", this being the Irish spelling. The spirit is scotch (as per image of Willie) and should have the Scottish spelling, "Whisky".
Skinner is wearing yellow karate belt after the first day of karate class. You need months of training before you can wear yellow belt.