Meta-data contained in the xs:appinfo of an element, expressing a unit of measure, as defined by the SI (ISO/IEC 80000 and NIST URI) and IEC Technical Committee (TC 25, Quantities and units) standards. Units are defined as an equation using the SI and IEC prefixes and units, possibly combined using multiplication and division operations. Specifically, units are expressed using the SI and IEC unit quantities (as defined in the open enumeration, UnitQuantityEnum), optionally preceded by a prefix (as defined in the open enumeration, UnitPrefixEnum), and combined using "*" for mulitplication, "/" for division and parentheses ("(" and ")"). The units defined in the UnitQuantityEnum are one of the 7 base quantities, 22 derived quantities, and 24 "outside" but "acceptable" quantities defined by SI, and 4 extended units (Bit, Byte, Number and Number/Interval).

Type Derivation Tree

xs:string (restriction)

usm-meta:UnitDefinition

Derivation:

restriction of xs:string