Join Date: May 2006
Location: 5 miles from EMA
Programs: BD RIP, BAEC Pleb, VS Pleb, Accor Pleb, HHonors Gold, Big White Season Pass
Posts: 6,335
You need to call Thai airways and ask.
When I travelled at the of the end of last year, this information wasn't required in advance but that's not to say that it's so new that nobody has heard of it yet.
You have to give this information on your landing card anyway and hand it in at immigration.