I recently bought a copy of Moby-Dick belonging to the Penguin English Library Series. I found that at the end of the book, there are no annotations as other versions of the same book commonly do, such as Penguin Classics or Oxford World Classics. There are indeed a couple pages of Natural Terms but they are different from some helpful explanatory notes. I haven't started reading it but I feel a bit disappointed for having bought it.
Does this (no notes) happen to all Penguin English Library books? Is yes, why do they cut notes off?
Or does it only apply to Moby-Dick? If yes, why?