gml:ParameterValue 

gml:ParameterValue is a parameter value, an ordered sequence of values, or a reference to a file of parameter values. This concrete complex type may be used for operation methods without using an Application Schema that defines operation-method-specialized element names and contents, especially for methods with only one instance. This complex type may be used, extended, or restricted for well-known operation methods, especially for methods with many instances.

Element Information

Model

(gml:value | gml:dmsAngleValue | gml:stringValue | gml:integerValue | gml:booleanValue | gml:valueList | gml:integerValueList | gml:valueFile) , gml:operationParameter
Children: gml:booleanValue, gml:dmsAngleValue, gml:integerValue, gml:integerValueList, gml:operationParameter, gml:stringValue, gml:value, gml:valueFile, gml:valueList

Source 

<element name="ParameterValue" type="gml:ParameterValueType" substitutionGroup="gml:AbstractGeneralParameterValue">
  <annotation>
    <documentation>gml:ParameterValue is a parameter value, an ordered sequence of values, or a reference to a file of parameter values. This concrete complex type may be used for operation methods without using an Application Schema that defines operation-method-specialized element names and contents, especially for methods with only one instance. This complex type may be used, extended, or restricted for well-known operation methods, especially for methods with many instances.</documentation>
  </annotation>
</element>

Sample