title: Escaping plus signs doesn't work
body: <p>I'd like to delete all lines with 3 plus signs:</p>
  
  <pre><code>+++ 3 plus signs
  + 1 plus sign
  +++ 3 plus signs
  </code></pre>
  
  <p>Here's my sed command, escaping the plus signs after beginning of line</p>
  
  <pre><code>sed '/^\+\+\+/d'    -&gt; This erase all lines
  sed '/^+++/d'       -&gt; This works and show only the 1 plus sign line
  </code></pre>
  
  <p>Why? Is there any problem while escaping the plus sign?</p>