New titles are always announced publicly on a Thursday at 9am Pacific, at which time the Matching Pre-Order for the Numbered, Lettered and Roman Numeral editions will begin for owners who have rights to the latest title. These owners will have until 8am on the Saturday of the announcement week to place their order. At that time, if any copies are still available, they are opened up for public pre-order.
Depending on how many copies are still available, remaining Numbered, Lettered and Roman Numeral copies are sold either through a lottery or directly through the online store. Copies which go on sale directly tend to sell quickly, so it’s worth being ready when public pre-order opens.