We got it also when we bought our initial purchase at BCV. I thought it was a little strange also. Its' a whole long form entitled "Acknowledgement of Spa option". From what I understand it just tells you that you can get a discount for 20% off spa services.
The last paragraph reads: "The Disney VactionClub World of Attractions Program Spa Option is an incidental benefit as defind in 721.075, Florida Statutes and is offered to prospective purchasers in the vacation ownership plan. The Disney VacationClub World of Attractions Spa Option is available for your use for a period of 3 years or less after the first date that the vacationownership plan is available for your use. The availabity of the Spa Otion may or may not be renewed or extend." etc