The present document: ? defines the system architecture and operations needed for a Universal Communications (UCI) implementation capitalizing on existing and emerging standards; ? identifies and documents the standards that are available (or that will be available) to enable the UCI to be implemented. In line with the above one of the prime requirements during development of the UCI concept has been to minimize the number of specialized technical requirements necessary for its implementation. Similarly the assumption has been that most of the functionality necessary to put UCI into practice will appear as part of the natural evolution of a future communications network architecture (the rapid evolution of services such as Presence and Location Based Services indicate that this assumption is realistic). With regard to standardization@ the approach taken has been to avoid promoting the creation of new standards solely for the purpose of creating UCI systems when existing or developing standards can be used@ amended@ or extended. The main UCI functional entities are described in clause 6. Clauses 7 and 8 describe the required capabilities of UCI systems and list the technical requirements for UCI. Details of UCI dialogues@ services@ processes are contained in clause 9. Descriptions of communication using UCIs and of how UCI assists in personal privacy protection follow in clauses 10 and 11. Descriptions of the data handled in UCI systems and a UCI Security Framework are in clauses 12 and 13. Finally@ in the main document@ a brief introduction to UCI administrative issues and to the principal standards that could support UCI is contained in clauses 14 and 15. Annex A contains a number of scenarios that illustrate the UCI being used in everyday tasks. Each scenario describes how UCIs might be used in realistic communications related situations. Both the user experience and key elements of underlying system behaviour that produces that experience are shown. The scenarios: ? show how meeting the user requirements described in Annex B enables realistic and powerful usage scenarios to be delivered; ? help to identify and validate the system capabilities that are needed to deliver the required behaviour of UCI-based communication. Annex B contains a systematic analysis of the user requirements (first defined in EG 201 940 [1]) which have been used to define the UCI architecture. Each requirement is described in detail with particular reference to which requirements are mutually supportive and which are potentially in conflict. Annex C lists Standards Bodies which are potentially related to the UCI Technical Requirements. Annex D gives a summary of security mechanisms that may be of relevance to UCI. Annex E is a security risk assessment of UCI@ primarily from the end-user security perspective. Annex F draws comparisons between UCI and ENUM.