ITU-T Recommendation E.166/X.122 Series E: Telephone network and ISDN. Operation, numbering, routing and mobile services…Series X: Data networks and open system communication…Numbering plan interworking for the E.164 and X.121 numbering plans

ITU-T Recommendation E.165.1 Series E: Telephone network and ISDN. Operation, numbering, routing and mobile services…Use of escape code "0" within the E.164 numbering plan during the transition period to implementation of NPI mechanism ITU-T Recommendation E.165 Telephone network and ISDN. Operation, numbering, routing and mobile service. Timetable for coordinated implementation of the full capability of the numbering plan for the ISDN ERA (recommendation E.164) ITU-T Recommendation E.164.3 Series E: Overall network operation, telephone service, service operation and human factors… Numbering plan of the international …Principles, criteria and procedures for the assignment and reclamation of E.164 country codes… ITU-T Recommendation E.167 Telephone network and ISDN. Operation, numbering, routing and mobile service. ISDN network identification codes ITU-T Recommendation E.168 Series E: Overall network operation, telephone service, service operation and human factors. International operation – Numbering plan of the international telephone service. Application of E.164 numbering plan for UPT ITU-T Recommendation E.168 (2002) - Amendment 1 Series E: Overall network operation, telephone service, service operation and human factors…Application of E.164 numbering plan for UPT. Amendment 1: New Appendix I