E.123

E.123 is a recommendation by the International Telecommunication Union (ITU) that provides a standardized format for displaying telephone numbers and related address information. It is part of the E-series of Recommendations, which deals with telecommunications and numbering. E.123 sets guidelines for the presentation of different types of numbers, including international, national, and local phone numbers. Its primary goal is to improve the interoperability and clarity of telephone number representations across different countries and systems. The format specified by E.