ISO 4217 codes (STANAG 1059, 9th edition) use "X" codes for imaginary exercise countries ranging from XXB for "Brownland" to XXR for "Redland", as well as for major commands such as XXE for SHAPE or XXS for SACLANT. Consequently, ISO 4217 can use "X" codes for non-country-specific currencies without risk of clashing with future country codes. The inclusion of EU (denoting the European Union) in the ISO 3166-1 reserved codes list, allows the euro to be coded as EUR rather than assigned a code beginning with X, even though it is a supranational currency. The ISO 4217 standard includes a crude mechanism
ISO 31 ISO 31 ISO 31 (Quantities and units, International Organization for Standardization, 1992) is a deprecated international standard for the use of physical quantities and units of measurement, and formulas involving them, in scientific and educational documents. It is superseded by ISO/IEC 80000. The standard comes in 14 parts: A second international standard on quantities and units was IEC 60027 . The ISO 31 and IEC 60027 Standards were revised by the two standardization organizations in collaboration (, ) to integrate both standards into a joint standard "ISO/IEC 80000 - Quantities and Units" in which the quantities and equations used with