Nevermind! I found the function responsible for the special characters replacement.
For those of you wondering, the function resides in
save_content.processor.php around line
570.
function stripAlias($alias) {
global $modx;
if (strtoupper($modx->config['modx_charset']) == 'UTF-8')
$alias = utf8_decode($alias);
$alias = strtr($alias, array (
chr(196) => 'Ae', chr(214) => 'Oe', chr(220) => 'Ue', chr(228) => 'ae', chr(246) => 'oe', chr(252) => 'ue', chr(223) => 'ss'));
$alias = strip_tags($alias);
//$alias = strtolower($alias);
$alias = preg_replace('/&.+?;/', '', $alias); // kill entities
$alias = preg_replace('/[^\.%A-Za-z0-9 _-]/', '', $alias);
$alias = preg_replace('/\s+/', '-', $alias);
$alias = preg_replace('|-+|', '-', $alias);
$alias = trim($alias, '-');
return $alias;
}
