CG = Certificate of Gameness Dog has qualified in the Open class at an American Working Terrier Association trial, negotiating through 30 feet of  9"x 9" 3-sided wood tunnels that are buried in the ground and scented and that have a live rat at the end of the den (the rat is behind bars for protection from injury by the dog), thus the dog has been shown willing to enter a den, find the quarry, and work to show where the quarry is located