conveys letter post items on behalf of the person granted authorisation according to (1) above, as a vicarious agent or as a person employed in the performance of its obligations;
conveys letter post items enclosed with another item and relating solely to the contents of that item;
conveys letter post items in such a way that individual recorded items, in the interest of rapid, reliable conveyance, are accompanied at all times on the journey from sender to addressee by a person who has access to the item at all times and who can make the necessary arrangements (courier service).