HTML5 Summary tag in editor

You can use the $allowed_tags global. Add the following to your functions.php file.

global $allowedtags;
$allowedtags['summary'] = array('class' => array());

Add more attributes within the array similar to the class element. You can learn more on Otto’s post here:

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)