ISO 4217 "ruble". In addition to codes for most active national currencies ISO 4217 provides codes for "supranational" currencies, procedural purposes, and several things which are "similar to" currencies: The use of an initial letter "X" for these purposes is facilitated by the ISO 3166 rule that no official country code beginning with X will ever be assigned. Because of this rule ISO 4217 can use X codes without risk of clashing with a future country code. ISO 3166 country codes beginning with "X" are used for private custom use (reserved), never for official codes. For instance, the ISO 3166-based NATO country
ISO/IEC JTC 1/WG 7 ISO/IEC JTC 1/WG 7 ISO/IEC JTC 1/WG 7 Sensor Networks (WGSN) is a standardization working group of the joint technical committee ISO/IEC JTC 1 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), which develops and facilitates standards within the field of sensor networks. The international secretariat of ISO/IEC JTC 1/WG 7 is the Korean Agency for Technology and Standards (KATS), located in the Republic of Korea. ISO/IEC JTC 1/WG 7 was established in October 2009 via Resolution 34 of the 24th JTC 1 Plenary in Tel Aviv. The group was established with the intention of