The present document is one of the parts of the specification of the Digital Enhanced Cordless Telecommunications (DECT) Common Interface (CI). The present document specifies the identities and addressing structure of the Digital Enhanced Cordless Telecommunications (DECT) Common Interface (CI). There are four categories of identities to be used for identification and addressing in a general DECT environment. These four categories are: • Fixed Part (FP) identities; • Portable Part (PP) identities; • connection-related identities; • equipment-related identities. Fixed part identities and portable part identities are used for: • access information from fixed parts to portable parts; • access requests from portable parts; • identification of portable parts; • identification of fixed parts and radio fixed parts; • paging; • billing. These identities support: • different environments, such as residential, public or private; • supply to manufacturers, installers, and operators of globally unique identity elements with a minimum of central administration;