<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="http://example.org/fhir/StructureDefinition/no-email-reason" />
  <name value="NoEmailReason" />
  <status value="active" />
  <kind value="complex-type" />
  <abstract value="false" />
  <context>
    <type value="element" />
    <expression value="Patient" />
  </context>
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <snapshot>
    <element id="Extension">
      <path value="Extension" />
      <short value="No email reason" />
      <definition value="The reason why the patient did not provide an email address." />
      <min value="0" />
      <max value="1" />
      <type>
        <code value="string" />
      </type>
    </element>
  </snapshot>
</StructureDefinition>