We extend the theory about terminological default reasoning by using a logical base language that can represent spatioterminological phenomena. Based on this description logic language called ALCRP(S2), which is briefly introduced, we discuss algorithms for computing so-called extensions (“possible worlds”) of a world description and a set of defaults. We conclude with an application of the theory to problems in visual query systems and demonstrate the significance of the theory for spatioterminological reasoning in general and spatioterminological default reasoning in particular.