Correct Name Capitalization in PHP

function titleCase($string) 
{
	$word_splitters = array(' ', '-', "O'", "L'", "D'", 'St.', 'Mc');
	$lowercase_exceptions = array('the', 'van', 'den', 'von', 'und', 'der', 'de', 'da', 'of', 'and', "l'", "d'");
	$uppercase_exceptions = array('III', 'IV', 'VI', 'VII', 'VIII', 'IX');
 
	$string = strtolower($string);
	foreach ($word_splitters as $delimiter)
	{ 
		$words = explode($delimiter, $string); 
		$newwords = array(); 
		foreach ($words as $word)
		{ 
			if (in_array(strtoupper($word), $uppercase_exceptions))
				$word = strtoupper($word);
			else
			if (!in_array($word, $lowercase_exceptions))
				$word = ucfirst($word); 
 
			$newwords[] = $word;
		}
 
		if (in_array(strtolower($delimiter), $lowercase_exceptions))
			$delimiter = strtolower($delimiter);
 
		$string = join($delimiter, $newwords); 
	} 
	return $string; 
}