The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to
ITU-T E.168-1993 history
1993ITU-T E.168-1993 Application of E.164 Numbering Plan for UPT Study Group II; 9 pp