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/SC 17/WG 1 Sub-Committee 17 administered standards. ISO/IEC JTC 1/SC 17/WG 1 ISO/IEC JTC 1/SC 17/WG 1 is a working group within ISO/IEC JTC1 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), that facilitates standards development within the field of cards and personal identification. A national delegation of experts from various countries meet in person at WG1 to discuss and debate items detailed in a meeting agenda until a consensus is reached. These items include: draft standards, draft test methods, questions from the industry, proposals for new work items or other aspects relating to the Standards and Test