When you pre-register by March 1, 2016 you will have priority to pick your stateroom and book & deposit it before the general public. You will be given 30 days from the time you are notified to either book/deposit your room or ask for your $200 pre-registration fee to be refunded to you. After 30 days the fee is non-refundable (you can book a room later, based on availability, and still have this credited towards your stateroom deposit).
Pre-registration is limited to 100 rooms / spots in the group.