title: Caret notation and control characters in Vim
body: <p>In Vim (or in a terminal?), control characters and their caret notation cannot be distinguished, like <code>Enter</code> vs. <code>C-M</code>. However, there is an only exception; <code>BS</code> vs. <code>C-H</code>.<br>
  Why are they only privileged?</p>
  
  <p>For example, if you map <code>Enter</code> to <code>NOP</code>, also <code>C-M</code> will be mapped. Other many control characters have the same behavior. On the other hand, <code>BS</code> and <code>C-H</code> can be mapped to different keys respectively.</p>
  
  <pre><code>:map &lt;Enter&gt; &lt;NOP&gt; // also &lt;C-M&gt; will be mapped
  :map &lt;BS&gt; &lt;NOP&gt;    // only &lt;BS&gt; will be mapped, &lt;C-H&gt; won't
  </code></pre>