I couldn't find anything on the member website about room discounts but I found what was in my paperwork when I bought in 1999. I have not bought since so I don't have anything more recent.
Member Rental Discount at DVC Resorts. Members may receive a discount off of the published rack rate at any DVC resort, subject to the following conditions:
1) All cash reservations must be requested through Member Services
2) Member Rental Discounts may be requested by a Member or an Associate. However, a Member must personally occupy the rental Vacation Home for all nights reserved on a cash basis in order to receive the Member Rental Discount. A DVC Member Card or photo ID may be required by the DVC Resort to verify eligibility for the Member Rental Discount.
3) Members and their Guests staying through the Member Rental Discount are eligible for the optional Member Benefit programs that may be available at that DVC Resort.
4) DVD may adjust or restrict the Member Rental Discount at some or all DVC Resorts based on demand, seasonality, or other factors. The Member Rental Discount at all DVC Resorts is subject to availability and blockout periods.
5) DVD may offer Members a Member Rental Discount at their Home Resort (subject to availability and blackout periods). Member Rental Discounts at DVC Resorts other than the Member's Home Resort may be offered from time to time at the discretion of DVD.
6) Housekeeping services for members staying on the Member Rental Discount is the same as for Members on a stay reserved with Vacation Points.
7) Cancellation of reservations made using the Member Rental Discount must be received at least five (5) days in advance of the arrival date. In the even that such a reservation is not canceled at least five (5) days in advance of the arrival date, the Member and/or Guests will be assessed a charge equal to the value of the first night's accommodations for such reservation.