<p><a href="https://meta.stackexchange.com/q/291824/178179">Gold-badge holders and moderators can now edit duplicate links</a> (2017-03-03):</p>

<blockquote>
  <p>As of a few minutes ago, if you have a gold tag-badge for a tag
  associated with a question that's been closed as a duplicate, you can
  edit the duplicate links to replace, add, remove or re-arrange them:</p>
  
  <p><a href="https://i.stack.imgur.com/Xqelw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Xqelw.png" alt="edit link in duplicate banner"></a></p>
  
  <p><a href="https://i.stack.imgur.com/nHY0y.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nHY0y.png" alt="link editor"></a></p>
  
  <p><a href="https://i.stack.imgur.com/rpwvl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rpwvl.png" alt="revision list"></a></p>
  
  <p>These changes are tracked in PostHistory to allow anyone to detect
  abuse, while the results update the PostLinks table so that existing
  logic continues to work (I mention this because some of you may wish
  to lean on <a href="http://data.stackexchange.com/" rel="nofollow noreferrer">SEDE</a> for observing how
  this works out, once it gets updated).</p>
</blockquote>
