title: bitbucket web: highlighted or greyed-out merge commits?
body: <p>I'd like to know why, in the commits view of the bitbucket webui, I see some merge commits with the M greyed-out whereas others have it in color.</p>
  
  <p>How can this be setup or how are they detected?</p>
  
  <p>I wasn't able to find any documentation about this behavior.</p>