This part of the Digital European Cordless Telecommunications (DECT) Common Interface specifies the identities and addressing structure. It is Part 6 of a series of 9. 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; - multiple access rights for the same portable; - large freedom for manufacturers@ installers@ and operators to structure the fixed part identities@ e.g. to facilitate provision of access rights to groups of DECT systems; - roaming agreements between DECT networks run by the same or different owners/operators; - indication of handover domains; - indication of location areas@ i.e. paging area; - indication of subscription areas of a public service. This specification also provides for length indicators and other messages that can override the default location and/or paging area and domain indications given by the structure of the identities. Connection related identities are used to identify the protocol instances associated with a call and are used for peer-to-peer communication. Equipment related identities are used to identify a stolen PP and to derive a default identity coding for PP emergency call set-up. Coding of identity information elements for higher layer messages is found in ETS 300 175-5 [5]@ subclause 4.7. User authentication and ciphering need additional key information and is not within the scope of this part@ but is covered in other Parts of ETS 300 175@ e.g. Part 7.