A telecommunications addressing system/method allowing selection of a telephone instrument device (TID) using arbitrary identifiers is disclosed. The system/method allows a source TID (STD) to select a target TID (TTD) by the use of a Target Telephone Identifier (TTI) data string rather than a traditional numeric telephone identification (NTI). This TTI is then indexed within a TTI/NTI mapping server (TMS) that functions as a hierarchical repository of TTI/NTI mappings. STD/TTD communication is established by first performing a lookup of the STD-selected TTI within the TMS to identify the NTI of the TTD. Once the NTI of the STD has been identified by the TMS, communication between the STD and TTD is established using the NTI via the normal public switched telephone network (PSTN). TMS TTI lookup may be performed via STD TID web application and/or via PSTN infrastructure interface.