Horntail?

Could somebody give a few more details of how this works?
I thought you needed to set up an expedition, same as Zakum.
So is there no longer an expedition requirement, or do you really mean that 30 expeditions can sign up, but only the expedition leaders can go in to solo?
Or do 30 HT solists band together and sign up as a single expedition after server check, and any member of that expedition can solo later, as long as the expedition is preserved?

Make an expedition of at least 6 people to enter. Each time one person enters, it counts as a spot. So 15 people could fill up the 30 slots. You don't have to keep the expedition, as long as you were one of the first 30 spots then you can keep re-entering until the next SC/patch.