EnumValues is defined in OPC 10000-8 as Property of the MultiStateValueDiscreteType. In this specification the Property is used for Variables, independent of the VariableType.
The Property uses an array the EnumValueType. When an IODD defined SingleValue is mapped to an entry of the array, the following rules apply:
The IODD value is mapped to the OPC UA value.
The IODD name is mapped to the OPC UA displayName. The IODD value contains a TextRefT referencing a text, potentially in several languages. The displayName is LocalizedText, thus also different locales can be provided. The localeId shall contain the corresponding language, and the text the referenced text.
The OPC UA description shall be left empty.