Originally Posted by skyrider007
I have no idea about the "I" booking class. But the seat number indicates that you're flying business. I believe THAI flies the B777-200ER to Tokyo, which is fitted with the new angled flat seat. And 12B would be an aisle seat.
TG 676 is a 3 class plane (for the moment) and mostly a 747. 12B is an upper deck aisle seat on that plane.
I class is an award business class code