A collection of collections and a specialization of type of object (q.v.). Each instance of spatially disjoint object type is a collection C of spatial things (see spatial thing), where each of the spatial things in C is spatially disjoint with the other spatial things in C.

For example, the collection dog is an instance of spatially disjoint object type, since dogs do not spatially overlap. Even pregnant dogs do not spatially overlap the pups they bear; rather, pregnant dogs contain their unborn pups. Other instances of spatially disjoint object type include line of latitude, compact disc, and planetary body. An important specialization of spatially disjoint object type is region type whose instances are non-overlapping region types (a collection of specializations of geographical region, such as city and true continent).