For those who've never played 1E, there were demon Types, which in 2E became generic types. For example, in 1E there are only six Type VI demons known to exist (one is named Balor in the MM1). In 2E, a balor is a generic type of demon, and is essentially the Type VI demon, only made into a generic name (they're all called "balors").
Well, in the DMG, they list all the names of the Type VI demons!

Balor, Alzoll, Errtu, Ndulu, Ter-sath, and Wendonai
Same for the other types.
How cool is that? How crazy is that...that I've never really looked closely at that section in 35 years? That's why the 1E DMG is so cool - 35 years later I'm still finding new info!
