title: How to unmap TAB and do not make Ctrl-I invalid in VIM
body: <p>When I use vim in normal mode, I often press the TAB key accidentally, the key TAB do the same thing as Ctrl-I in default. I want to make the key TAB do nothing, so I put this line in the vimrc file:</p>
  
  <pre><code>nmap &lt;TAB&gt; :echo&lt;CR&gt; 
  </code></pre>
  
  <p>Thus, the key TAB will do nothing, but this made the key Ctrl-I do nothing too.
  So, how to make the TAB do nothing and the Ctrl-I work well as before in vim (in normal mode) ?</p>