ref:Note 

Notes can contain reference material; use this element when the note is published as a standalone document.  There is a separate element for footnotes within other references.

Element Information

Model

Source 

<element name="Note" type="string" substitutionGroup="link:part" id="ref_Note">
  <annotation>
    <documentation xml:lang="en">Notes can contain reference material; use this element when the note is published as a standalone document. There is a separate element for footnotes within other references.</documentation>
  </annotation>
</element>

Sample