It seems as if there has been a change in the constellation of UEFA's Referee Committee. Former EURO 2008 referee Kyros Vassaras of Greece is not appearing in the updated list of the committee's members of the 5th December 2013.
Having been specially responsible for youth tournaments, where he was frequently present as coordinator and observer, Vassaras seems to have quit the committee for so far unknown reasons. According to the document issued by Europe's football governing body, there is nobody replacing him. A statement by UEFA is awaited and will be communicated here as soon as issued.