<xsd:element maxOccurs="unbounded" name="gradeFromCourse" >
  <xsd:complexType>
    <xsd:sequence>
      <xsd:element name="courseInstance" type="tns:courseInstanceT"/>
      <xsd:element minOccurs="0" name="grade" type="tns:gradeT">
        <xsd:key name="gradesFromCoursesWithPersonalData_uniqueGradingScheme">
          <xsd:selector xpath="tns:value"/>
          <xsd:field xpath="@gradingScheme"/>
        </xsd:key>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>
</xsd:element>