American Numbering Plan (NANP) use 011. Certain post-Soviet states continue to use 810 which was the universal IDD code across the Soviet Union. Other prefixes (000, 001, 0011, 119, etc.) are also in use in a small number of countries. Some countries require that the prefix 00 is followed immediately by the so-called carrier selection code, i.e., a numeric code that routes the call via a specific provider for international connectivity. Some countries may require that any carrier selection codes precede the international call prefix. Some countries also offer simplified dialling arrangements for calls to neighbouring countries, usually by removing the need of dialling an international call prefix and the country code. To avoid confusion especially in international context, a plus sign (+) is often used as a graphic symbol of the international access code; it informs the caller to replace it with the prefix code appropriate for their country. Additionally, the GSM mobile telephony standard allows the use of the plus sign in place of the international call prefix; the mobile operator automatically converts the plus sign to the correct international access prefix for the country where the phone is actually being used. This permits the use of the same electronically stored directory number when calling from any country. Example The fictitious number (02) 3456 7890 in Sydney, Australia, is published in the form +61 2 3456 7890 for international use. In countries participating in the North American Numbering Plan, such as the United States, Canada, and some Caribbean nations, this number is dialed as 011 61 2 3456 7890, with 011 being the international call prefix for the NANP and 61 being the country calling code of Australia. From most of the rest of the world, the international access code is 00, so that the call is dialed as 00 61 2 3456 7890, as recommended by the regulations of the ITU. (For Australians who wish to dial international numbers, the international access code when calling from Australia is 0011.) See also List of country calling codes List of international call prefixes References International telecommunications Teletraffic