A collection of collections of collections. type of collection is the collection of all (and only) types of Collections. More precisely, a thing COLLTYPE is an instance of type of collection if and only if COLLTYPE is a non-empty collection all of whose instances are collections. Example: type of person classified by culture, each of whose instances is the collection of all persons who participate in some particular human culture, is an instance of type of collection. Important specializations of type of collection include disjoint classification scheme, sibling disjoint collection type, and type of collection type.