This document specifies the Directory Services, using the concepts of global name space and cell name space. It defines application programming interfaces based on the Directory Services (XDS) interface (C317), OSI-Abstract-Data Manipulation (XOM) (C315), and Federated Naming: The XFN Specification . It also defines the Global Directory Service and Cell Directory Service. This document provides a portability guide to application programs using Directory Services and a conformance specification for implementation. This document includes text excerpted and/or derived from the Technology (AES) Specification.