Originally Posted by
Dave Noble
At the moment he is ticketed in economy with a voluntary downgrade; to go in business class it needs to be rebooked into D class and so should need a reissue
Indeed, but I can never understand why anyone would do that. If you find yourself in this situation get the ticket coupon issued open-dated in D and get a separate reservation for that sector only in L and waitlisted D. That way you can turn up with the D ticket and take the L seat if no D clears, but if it does then no reissue.