<xs:simpleType name="DiameterModifierEnumType"><xs:annotation><xs:documentation>(ISO specific) The DiameterModifierEnumType enumerates values that describe diameter modifiers for threaded datum features.</xs:documentation></xs:annotation><xs:restriction base="xs:NMTOKEN"><xs:enumeration value="PD"/><xs:enumeration value="MD"/><xs:enumeration value="LD"/></xs:restriction></xs:simpleType>