unicode-bidi

<xs:attribute name="unicode-bidi">
  <xs:simpleType>
    <xs:restriction base="xs:token">
      <xs:enumeration value="normal"/>
      <xs:enumeration value="embed"/>
      <xs:enumeration value="bidi-override"/>
      <xs:enumeration value="inherit"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>