
  <p>
  Define which elements of a single item of a feed (= <em>Sources</em>) map to which content pieces in Drupal (= <em>Targets</em>). Make sure that at least one definition has a <em>Unique target</em>. A unique target means that a value for a target can only occur once. E. g. only one item with the URL <em>http://example.com/content/1</em> can exist.
  </p>
  