Edited sentence: Ambiguity reduced by removal of the serial comma is often contextually reduced, rather than grammatically.For instance, in the case of the maid and pet rabbit, it is only because the reader knows that in the context of the sentence a pet rabbit is not a maid that ambiguity is reduced by omission of the serial comma.In a children's story featuring animals as anthropomorphic characters, Betty could very well be both a maid and a pet rabbit.To resolve such ambiguity grammatically requires rearranging the order of the list elements so that Betty comes later in the series, in which case using the serial comma is a way to avoid ambiguity