This Recommendation establishes general principles for Universal Personal Telecommunication (UPT). Detailed provisions may be found in Recommendation F.851. UPT enables access to telecommunication services while allowing Personal Mobility. It enables each UPT user to participate in a User-defined set of subscribed services and to initiate and receive calls on the basis of a personal, network-transparent UPT Number across multiple networks at any terminal, fixed or mobile, irrespective of geographic location, limited only by terminal and network capabilities and restrictions imposed by the network operator.