In this paper we describe the advertisement of the capabilities or the know-how of an ``object'' (like a business partner, an employee, a software component, a Web site, etc.). The capabilities are structured and organized in order to be used when searching for objects that satisfy a given objective or that meet a given need. One of the originality of our proposal is in the nature of the answers the intended system can return. Indeed, the answers are not Yes/No answers but when no single object meets the search criteria, we attempt to find out what a set of ``complementary'' objects that do satisfy the whole search criteria, every object in the resulting set satisfying part of the criteria. Description Logics (DL) is used as a knowledge representation formalism and the determination of the ``complementary objects'' is founded on the DL complement concept.