I'm quite sure that information processing is as varied as DNA. Many find it difficult enough to try to fit under one of 16 general categories let alone more. I think it would be quite an achievement to get accurate specifications for the 16 general types because, by definition, subcategories should all fit under the same general category; if not, the specification of the general category has to be wrong - one shouldn't be able get a building permit to add rooms to a house that's already on a shaky foundation....
a.k.a. I/O