Despite the many comic book editors and writers who dislike the terminology of numbered ("Earth-616") or lettered ("Earth-A") earths, and the virtually total ignorance of science that underpins that hostility, the general fan community and broader consumer audience obviously DO like to number all the parallel earths in fiction, and to go much further, actually seeing how all the earths "fit in" together in one cross-company omniverse.

Alan Moore and Alan Davis christened the Marvel Universe Earth-616 in a story entitled "Rough Justice," in the Marvel UK anthology comic "The Daredevils" (July 1983). This number is high enough to imply many other earths and distant enough from the "historical" earlier parallel earths of DC not to overlap significantly.

DC is careful to respect the use of Earth-616 for the Marvel Universe, or what the current Marvel writers have left of it.

DC also has a colossal number of other numbered or lettered universes. Most other comic companies have added only a handful of worlds to the total.