Q. What is the Rule of Four?
A. The Rule of Four guideline is that you cannot book and travel on the Disney Collection (excluding hotels at
Disneyland Resort in California and Tokyo Disney Resort) and Concierge Collection vacations within the last 4 months of your Use Year.
However, you can travel in the last 4 months of your Use Year as long as you've booked your stay more than 4 months before the end of your Use Year.
https://disneyvacationclub.disney.go.com/faq/points/rule-of-4/
NOTE: The Rule of Four does not apply when booking at a
DVC Resort nor does it apply to RCI Exchanges. The Disney Collection consists of the non-DVC Disney Resorts and
Disney Cruise Line.