gml:UomIdentifier 

The simple type gml:UomIdentifer defines the syntax and value space of the unit of measure identifier.

Simple Type Information

Used By

Attributes gml:CoordinateSystemAxisType/@uom, gml:MeasureListType/@uom, gml:MeasureOrNilReasonListType/@uom, gml:MeasureType/@uom, gml:UnitOfMeasureType/@uom, gml:referenceSystem/@uom

Source 

<simpleType name="UomIdentifier">
  <annotation>
    <documentation>The simple type gml:UomIdentifer defines the syntax and value space of the unit of measure identifier.</documentation>
  </annotation>
  <union memberTypes="gml:UomSymbol gml:UomURI"/>
</simpleType>