<simpleType name="LabPermEnumType"> <restriction base="string"> <enumeration value="constant head"/> <enumeration value="falling head, constant tailwater elevation"/> <enumeration value="falling head, rising tailwater elevation"/> <enumeration value="constant rate of flow"/> <enumeration value="constant volume-constant head (by mercury)"/> <enumeration value="constant volume-falling head (by mercury), rising tailwater elevation"/> </restriction> </simpleType>