title: codeigniter allowed characters in url
body: <p>Using codeigniter I have a problems to pass variables in my back end like</p>
  
  <pre><code>http://localhost:4949/admin/delete_post/6/?action=delete
  </code></pre>
  
  <p>producing <code>The URI you submitted has disallowed characters.</code></p>
  
  <p>I know that this problem could be corrected from config.php <code>$config['permitted_uri_chars']</code>, but how could I exclude from filtering my backend and to permit this kind of structure and leave the frontend intact.</p>