First Run Discs are new models released, in most cases, with a special stamp that indicates or explicitly states First Run / First Flight. 

Some companies come out with a “Prototype,” which is a small run that precedes the 1st Runs. Dynamic Discs goes even farther. When they launch a new model, the first people to get it are the players on one of the teams — Dynamic Discs or Latitude 64. They get to show everybody who’s not on a Trilogy team what they can’t have.