Many larger restuarants and foodservice operations that utilize large quantities of lobster will purchase various grades of shelled lobster meats from vendors. They do this becuase it's less expensive than hiring people to cook and pick the lobster meat for them. You can purchase the lobster meat in the following grades.
Regular: picked meat from the whole lobster. Tail, leg, claw, knuckle and body meat in what is termed "natural proportions". Funny how natural always means junior size tail and claw meat eh?
TCK: Tail, Claw, and Knuckle meat. You'll find that many restuarants will use this for cold salads, seafood stuffings, imperials and the like. TCK meat can also be used as garnishes for soups and sauces.
TC: Tail and Claw meat. It is used for much the same things as above, although it is also used more in entrees as well.
All Tail: The explanation here is self evident. While I cannot speak to operations outside the USA, you will find that many Chinese and Asian Specialty restuarants inside the USA utilize All Tail and TC lobster meat regularly across their menus.
CK: Claw and Knuckle meat. Operations will purchase this grade as a less expensive option to the TCK grade of meat.
Broken: This is the picked lobster meat leftover from bodies and legs. A mistakenly chopped up tail or claw may also find its way in here. This is commonly used in casseroles, stuffings, and the like. When the flavor of the lobster meat is a higher priority than being able to see it is where you'll find this grade.
One thing to keep in mind when purchasing these items is that they still must be checked thoroughly for bits of shell and pieces of fibrous cartilage.