Patty and Selma are part of the Macbeth play. At the end of that segment, the director says that Homer is the only cast member still alive. Yet we never hear how Patty and Selma died, and they were missing from the ghosts that attacked Marge.
Queen Elizabeth's banner reads "Mission Accomplished" with two long or medial Ses in "mission". Words with two sequential Ses were written with one long s followed by a short s (the same s used in modern English).
There was never a king of Spain with the name Julio. The king that sent the Armada was Felipe (Philip) II.