(From Chef Resources) Beef Short Ribs can be cut from three different sections of beef. The most common short rib cut is the Back Rib (NAMP 124) which comes from the thick side of the prime rib. A second source, called Plate Short Ribs (NAMP 123 series), is found in the plate primal, which is found in the animal’s forequarter right below the rib primal. The last are called Chuck Short Ribs (NAMP 130) which come from right under the chuck from the first to the fifth rib, and can also go by the name Flanken Ribs.
Other names which beef short ribs go by include: braising ribs, crosscut ribs, English short ribs, Korean short ribs. As chefs, we can specify to our vendor which cut of short ribs we want by using the NAMP number. But in the supermarket it is sadly a different story as the section from which the beef short ribs are cut is rarely identified on supermarket labels. This is particularly frustrating as the three different kinds of short ribs have markedly different qualities. Short ribs that come from the plate primal have lots of good muscle tissue, but also a significant amount of fat. Rib primal short ribs don’t have as much meat to them as the plate variety, but are far more tender. Flanken ribs are tougher, and less fatty.
Regardless of which variety you’re dealing with, braising does a great job of breaking down the connective tissue that holds the meat to the bone. The constant contact with liquid at a higher temperature encourages the metamorphosis of collagen tissue into gelatin, which adds flavor and moisture to the muscle. Thankfully, there is more than just one way to achieve similar results: sous vide and BBQ. Sous vide is, without a doubt, the most efficient way to do achieve fork tender short ribs, but barbecuing, pressure cooking and even steaming all can provide excellent results. More info: http://www.chefs-resources.com/types-of-meat/beef/cuts-of-beef/beef-short-ribs/#ixzz4ecUKg7yR