For example, I have a 25-point resale contract which was purchased in 2012. I cannot use those points for cruises, hotel rooms or ABD but they wouldn't get me much anyway. What it does get me is a "blue card" membership. You can't get that today even if you could purchase just 25 points direct.
A little while later (2016, I believe),
DVC changed the rules so that you needed to purchase direct in order to get a blue card. They did not set a minimum amount and people began buying resale and adding a 25-point direct contract to qualify.
Over the years, DVC has increased that minimum buy-in for blue card status, grandfathered previous owners each time. At this point, you could have a anywhere from 25 points resale to 150 points direct (total) as the minimum that you own to qualify. And if you own multiple contracts, you best keep track of which ones qualify and which ones don't in the event that you decide to sell some of them.