I know the mutant part of the agreement. I just wouldn't be surprised if code names are part of it to. In X-Men they call him Peter but Marvel used Pietro. I don't believe either have called him Quicksilver yet. I don't think they bother with one off villains like him. Stroll in Ant-Man I don't recall being called Yellowjacket. I remember the uniform being called it. We do have Iron Man, Captain America, Hulk, Black Widow, Hawkeye, Falcon, Black Panther, War Machine, Ant-Man, and most of the known heroes. They just don't go around saying "Hey Hulk" or "Look out Hawkeye" they mostly call them by their real name. The public in the movies seem to know their code names.