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. This Recommendation | International Standard includes: • a framework for binding interfaces and a generic binding protocol (for both stream and operational interfaces); • a specification of the generic information structure of interface references (for both stream and operational interfaces); • representation(s) for interface references when transferred using standardized protocols; • identification of procedures for the management and transfer of interface references with respect to individual transparencies; • identification of node management interfaces related to binding and federation which create or transform interface references; • identification of requirements for quality of service information and for invocation of QoS or related measurement procedures. This Recommendation | International Standard provides an engineering description of the functionality needed to support the computational binding of objects in ODP systems. Security and support for group communication are important issues, but not within the scope of this Recommendation | International Standard.