title: Add custom content element layouts in TYPO3
body: <p>In TYPO3 I want to add several custom content element layouts to the existing ones of the default content type "Header". The custom layouts should make it possible, to make a header that is originally an H1 header look like H2 or H3, for instance.</p>
  
  <p>So I added this Typoscript code, that is supposed to add the additional options to the interface in the backend:</p>
  
  <pre><code>TCEFORM {
    tt_content {
      layout {
        altLabels {
          0 = abc
          1 = def
          2 = geh
          3 = Layout H1
          4 = Layout H2
          5 = Layout H3
        }
        removeItems = 6,7,8,9,10
      }   
    }
  }
  </code></pre>
  
  <p>As well as this, that should add the CSS classes:</p>
  
  <pre><code>tt_content.stdWrap.innerWrap.cObject = CASE
  tt_content.stdWrap.innerWrap.cObject {
      key.field = layout
  
      3 = TEXT
      3.value = like-h1
  
      4 = TEXT
      4.value = like-h2
  
      5 = TEXT
      5.value = like-h3
  }
  </code></pre>
  
  <p>However, of my 3 additional layouts, only one is added to the interface in the backend:
  <a href="https://i.stack.imgur.com/Sc9bq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Sc9bq.png" alt="enter image description here"></a></p>
  
  <p>No matter what I try, I can't get the other two layouts to be added to the dropdown list in the backend. What could be a reason for this?</p>