Telephone and ISDN Numbering Plan for Land Mobile Stations in Public Land Mobile Networks (PLMN) - Telephone Network and ISDN - Operation, Numbering, Routing and Mobile Service (Study Group II) 2 pp
A second method has been identified where the foreign PLMN uses a separate numbering plan
for visiting mobile stations where the number used is composed of a prefix indicating a foreign station followed by the country code of the country in which the sta