(PHP 5, PECL tidy >= 0.5.2)
tidy_config_count — Returns the Number of Tidy configuration errors encountered for specified document
   Returns the number of errors encountered in the configuration of the
   specified tidy object.
  
Returns the number of errors.
Example #1 tidy_config_count() example
<?php
$html = '<p>test</I>';
$config = array('doctype' => 'bogus');
$tidy = tidy_parse_string($html, $config);
/* This outputs 1, because 'bogus' isn't a valid doctype */
echo tidy_config_count($tidy);
?>