Does anyone know which specific segment (if there are 5 and only 4 are allowed in a region) is designated as the extra one? Is it the last one in sequence or can I designate any segment as being the extra one? The reason is that of the 5 segments that I want, only 4 have first class (the 3rd in sequence has only business class). I understand that I may buy extra segments in a lower class and am trying to work out if I can pay for a business class extra segment (to cover the 3rd segment in sequence), rather than a first class one (which relates to the last segment in sequence). Sorry if this sounds confusing.