From the points Sticky....
Discounts for cash stays at the MVCI resorts (and very infrequently, at certain of the Marriott hotels/resorts) are capacity-controlled and based on ownership status:
Presidential and Chairman's Club Members - 35% off (code "2VC")
Executive Members - 30% off (code "6VC")
Owners and Select Members - 25% off (code "7VC")
*MVW has clarified for TUG (see this post) that the Chase Marriott VISA 10% discount component is no longer available: "The Owner’s Discount can no longer be combined with any other discounts or offers."
*When checking availability on marriott.com, enter the appropriate code in the "Corporate/promotional code" box under "Special Rates."
*Owners/Members may also book cash nights through their my-vacationclub.com accounts. Click on "Explore the Marriott Vacation Club Resorts" in the "Plan and Book My Vacation" dropdown menu, then click on the "Rent More Nights" link in the column on the right. On the next page the field will be auto-populated with the appropriate code.
*Note the confirmations for stays using these discounts indicate that at check-in the certain eligibility will be verified. If unable to verify eligibility the cost for the stay may revert to rack rates.