code: public function checkPermission()
  	{
  		$bundles = Contao\System::getContainer()->getParameter('kernel.bundles');
  
  		// HOOK: comments extension required
  		if (!isset($bundles['ContaoCommentsBundle']))
  		{
  			$key = array_search('allowComments', $GLOBALS['TL_DCA']['tl_faq']['list']['sorting']['headerFields']);
  			unset($GLOBALS['TL_DCA']['tl_faq']['list']['sorting']['headerFields'][$key]);
  		}
  	}
docs: Check permissions to edit table tl_faq