It is called a Kahill Disposition. What that means is due to a case in Commonwealth vs. Kahill in 2004; the Registry of Motor Vehicles have to honor the decision of the court that treats a second offense OUI as a first offense. If it occurs more than 10 years from the date of the first drunk driving conviction, and what that means is that if you are charged with a second offense OUI, but that the court gives you the 24d program, it imposes all the similar penalties to a first offense; which can include the 45 days loss of license and the assignment of the 24d program that the RMV has to honor that disposition. It will allow you to obtain your license back provided that you have an ignition interlock installed in your car, and you will have to maintain that ignition interlock for a period of three (3) years. There is a little bit more to it than that, but that is the general terms to what a Kahill Disposition is.