Interface references are crucial to interworking between ODP systems and federation of groups of ODP systems. An interface reference embodies the information needed to establish bindings, including binding to objects at nodes that support several different communication protocols and binding to objects in different management domains. An interface reference further embodies the information required for the engineering mechanism to maintain bindings between computational objects in the presence of distribution transparencies such as migration transparency. They are the foundation of ODP location and relocation transparency.