Cut from the rib area, this is ribs 6 through 12 and some or all of 13. The backbone is cut completely away at one end and the other is to be cut so the ribs are all between 6 and 8 inches long (though in practice this varies). There can be substantial fat on the inside depending on how the ribs were cut.
The Rib Eye Roast meat is removed from the outside at the backbone end and any easily recoverable meat for grinding is removed from between the bones at the backbone end, thus the notches. The ribs become wider and flatter as they go down the side and below this cut they are made into Short Ribs. Each side shown in the photo was 15 inches long by 8-1/2 inches at the widest point and weighed 3-5/8 pounds.
More on Cuts of Beef.
Yield: - A 3-5/8 pound side was 2-1/8 pounds with bones subtracted (59%) but some of that was fat so don't count on more than 50% meat.
These are most commonly separated into individual ribs and grilled or broiled. Meat is not thick at any point so it will be cooked through when well browned on the outside. In the broiler, cut them in pairs or threes, partially separated, for stability, and finish separating them after broiling.