<complexType name="MeasureOrNullListType">
    <annotation>
      <documentation>List of numbers with a uniform scale.  
      A member of the list may be a typed null. 
      The value of uom (Units Of Measure) attribute is a reference to 
      a Reference System for the amount, either a ratio or position scale. </documentation>
    </annotation>
    <simpleContent>
      <extension base="gml:doubleOrNullList">
        <attribute name="uom" type="anyURI" use="required"/>
      </extension>
    </simpleContent>
  </complexType>