title: Add label to line in Highcharts
body: <p>I struggle to add a label on top of a line in highcharts .. for example suppose I have 4 series (all visible) with name <code>'data'</code>, <code>'mean'</code>, <code>'+1 std'</code>, <code>'-1 std'</code>:</p>
  
  <p><a href="https://i.stack.imgur.com/SO06u.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SO06u.png" alt="enter image description here"></a></p>
  
  <p>And I would like as a result:</p>
  
  <p><a href="https://i.stack.imgur.com/GA24G.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GA24G.png" alt="enter image description here"></a></p>
  
  <p>I am lost to know how to add it ... even with the documentation it seems I need the abscissa and ordinate to add for each label. How can I retrieve this information? Is it possible to add the label directly when I add the series?</p>
  
  <pre><code>        chart.addSeries({
              id           : 'mean',
              name         : 'mean',
              type         : 'line',
              lineWidth    : 1,
              lineColor    : 'rgba(0,128,0,0.9)',
              color        : 'rgba(0,128,0,0.9)',
              dashStyle    : 'LongDash',
              zIndex       : 5,
              data         : [[ext.dataMin, mean], [ext.dataMax, mean]],
              enableMouseTracking: false
          });
  </code></pre>
  
  <p>Notice that I <strong><em>do not want</em></strong> to display this information in a legend, but on the chart itself-</p>