gistfile1.txt

/*
 * Adding Parameters to Permalinks
 *
 */
add_filter( 'post_type_link', 'lc_append_query_string', 10, 2 );
function lc_append_query_string( $url )
{
    if(is_admin()) return $url;

    $query = array();

    if(isset($_GET['utm_medium']) && $_GET['utm_medium'] == 'frame') {
        $query[] = 'utm_medium=frame';
    }

    if(isset($_GET['utm_source']) && $_GET['utm_source'] == 'pillenstein_de') {
        $query[] = 'utm_source=pillenstein_de';
    }

    return (empty($query)) ? $url : $url.'?'.implode('&', $query);
}