Not to contradict you, MTH, but just for the sake of dicussion: The first "Pirates of the Carribean" movie had a subtitle. "The Curse of the Black Pearl". There've been many others as well. Especially recently. Master and Commander: The Far Side of the World, Lord of the Rings, Lemony Snicket, Harry Potter, Chronicles of Narnia... If they know it's going to be a series, as we know, then it is titled appropriately. There is a series title, and an episodic subtitle.