The DCE remote procedure call (RPC) facility supports an interface to the directory service that is specific to RPC and is layered on top of directory service interfaces; it is called the Name Service Independent (NSI) interface. NSI can manipulate three object classes: entries, groups, and profiles, which were created to store RPC binding information. NSI data is stored in CDS. Programming using this interface is discussed in the OSF DCE Application Development Guide - Core Components and OSF DCE Application Development Guide - Introduction and Style Guide .