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/TC 68 ISO/TC 68 ISO/TC 68 is a technical committee formed within the International Organization for Standardization (ISO), of Geneva, Switzerland, tasked with developing and maintaining international standards covering the areas of banking, securities, and other financial services. As the standards organization under ISO responsible for the development of all international financial services standards, ISO/TC 68 plays a key role in the development and adoption of new technologies in the banking, brokerage and insurance industries. Many of its current work projects involve developing ecommerce standards such as better online security for financial transactions, XML standards for financial transactions and standards to reduce