title: Auto Layout - Vertical spacing
body: <p>I'm Ctrl dragging from one UILabel to another to set a vertical spacing and I get the following dialog:</p>
  
  <p><img src="https://i.stack.imgur.com/SWpzs.png" alt="Auto Layout vertical spacing"></p>
  
  <ol>
  <li>What does this dialog mean? </li>
  <li>How do I set a vertical spacing between the 2 UILabels using this dialog?</li>
  </ol>