title: <C-S> mapping in Vim terminal issues
body: <p>I am having issues trying to map <code>&lt;C-S&gt;</code> in Vim terminal.</p>
  
  <p>The same mapping works in MacVim/gVim but not in the terminal. I have tried the below mappings in Terminal.app and the latest version of iterm2 and it fails to work.</p>
  
  <p>Is using <code>&lt;C-S&gt;</code> a bad idea because of terminal issues? If it is I was not aware (and could not find any information about it.</p>
  
  <pre><code>nnoremap &lt;script&gt; &lt;buffer&gt;&lt;C-s&gt; :call &lt;sid&gt;MyPrivateFunction()&lt;CR&gt;
  </code></pre>
  
  <p>Note though that the above mapping <em>works</em> in MacVim/gVim but not in the terminal.</p>
  
  <p>I have also tried the following variations:</p>
  
  <pre><code>cmap &lt;script&gt; &lt;buffer&gt;&lt;C-s&gt; call &lt;sid&gt;MyPrivateFunction()&lt;CR&gt;
  map &lt;script&gt; &lt;buffer&gt;&lt;C-s&gt; :call &lt;sid&gt;MyPrivateFunction()&lt;CR&gt;
  nnoremap &lt;C-s&gt; :call MyFunction()&lt;CR&gt;
  </code></pre>
  
  <p>Am I doing something wrong? And again, is it a bad idea to issue such a mapping? What would be the alternative?</p>