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
Standards organization national, regional and international scope; international organizations tend to have as members national organizations; and standards emerging at national level (such as BS 5750) can be adopted at regional levels (BS 5750 was adopted as EN 29000) and at international levels (BS 5750 was adopted as ISO 9000). Unless adopted by a government, standards carry no force in law. However, most jurisdictions have truth in advertising laws, and ambiguities can be reduced if a company offers a product that is "compliant" with a standard. When an organization develops standards that may be used openly, it is common to have formal