Since 2008, when the 20-reservation rule was created, DVC has never offered any clarification of the rule except for what it says. It states it applies per member, not just membership, but it is unknown whether having two use years and thus two memberships means the combined memberships are limited to 20.
Before 2008, a rather significant number of professional renters of DVC rooms had come into being. That was the result of the growth of the internet for rentals and different rules that DVC had at time. The only rental control rule was the generic rule that a member could not be using his ownership for a commercial purpose which was defined to include a pattern of reservations indicating that the member was using the ownership for commercial purposes. At the time, a member could also do an unlimited number of transfers, either in or out, but not both. Moreover, a member could be an associate member in an unlimited number of memberships.
That combination of rules allowed professional renters to create significant rental businesses. The owner could buy a large number of points (5,000 maximum at the time) and easily double or triple that by going into business with others who separately bought large numbers of points. Then the owner could also take in an unlimited number of transfers and rent those points, and get himself made an associate member with other owners and make reservations using their points. What was happening at the time was the professional renters were engaging in predatory reservations by making huge numbers of reservations at 11-months out in high demand rooms for high demand times, like Thanksgiving and Christmas, and then renting out those reservations, creating an 11-month issue when it otherwise did not exist, and thus preventing many members from making reservations. The 20-reservation rule was one of three rules created to correct the problem. The other two rules created limited transfers to one per use year and allowed a member to be an associate member on no more than 4 memberships. At the time, there was mention that a number of members were informed that their activities indicated a violation of the new rules. The rental businesses did not completely die but the problems they were creating were greatly reduced.
Since that time, DVC has said nothing about the 20-reservation rule, and for years there has been no mention of an actual enforcement of the rule. The further explanations being sought above have never been provided. The main rental businesses that exist today follow a different model than they did then. They are now brokers of reservations, acting as the go-between for owners who want to rent and those who want to rent from owners.