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 80000-1 "P". Annex C introduces the concepts of "power quantities" and "root-power quantities", and deprecates "field quantity". ISO 80000-1 ISO 80000-1:2009 is a standard describing scientific and mathematical quantities and their units. The standard, whose full name is "Quantities and units Part 1: General" was developed by the International Organization for Standardization (ISO), superseding ISO 31-0. It provides general information concerning quantities and units and their symbols, especially the International System of Quantities and the International System of Units, and defines these quantities and units. It is a part of a group of standards called ISO/IEC 80000. The standard is divided