<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="http://example.org/fhir/StructureDefinition/maternalLastName" />
  <name value="MaternalLastName" />
  <status value="active" />
  <publisher value="InterSystems Iberia" />
  <kind value="complex-type" />
  <abstract value="false" />
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension">
      <path value="Extension" />
      <short value="Maternal Last Name" />
      <definition value="This field stores the patient's maternal last name." />
      <min value="0" />
      <max value="1" />
      <type>
        <code value="string" />
      </type>
    </element>
  </differential>
</StructureDefinition>