AP stands for annul pass. Disney releases these rates oh, I'd say about once every three months for stays covering the next three months or so. The discounts can vary and they seem to range from about 20% to as much as 40% off hotel rack rates. They can be an incredible deal!
You do not have to possess an annual pass to book an annual pass discount rate, but you must show one at check in. So many people buy their annual pass vouchers then go get them activated at one of the parks or Downtown Disney before they check in to their hotel.
Melissa