title: Vim: Why does noremap not work in insert mode?
body: <p>Consider the unbinding of the arrow keys using</p>
  
  <pre><code> noremap &lt;Left&gt;  &lt;NOP&gt;
   noremap &lt;Right&gt; &lt;NOP&gt;
   noremap &lt;Up&gt;    &lt;NOP&gt;
   noremap &lt;Down&gt;  &lt;NOP&gt;
  </code></pre>
  
  <p>This works in normal mode, but it does <em>not</em> work in insert mode: one can still navigate with the arrow keys. As a countermeasure, one must include</p>
  
  <pre><code> inoremap &lt;Left&gt;  &lt;NOP&gt;
   inoremap &lt;Right&gt; &lt;NOP&gt;
   inoremap &lt;Up&gt;    &lt;NOP&gt;
   inoremap &lt;Down&gt;  &lt;NOP&gt;
  </code></pre>
  
  <p>But this doesn't really make sense to me, since I assume <code>map</code> and <code>noremap</code> should work in all modes, while prepending <code>n/v/x/s/o/i/l/c</code> specifies the mapping to work only within that specific mode. Is there a reason for this?</p>