The Generally Accepted Accounting Principles exist to ensure that American accountants are using the same or almost the same standards so that comparison of financial statements between or within a company is easy and accurate. They also promote transparency in accounting. The GAAP are set by the FASB.
According to the FoodTV Encyclopedia for Delmonico Steak, the Delmonico steak is a boneless top loin steak, which is also called a New York strip steak and a Kansas City strip steak. (With the bone in, it is usually called a club steak.)
The difference between a ribeye steak and a rib steak is that the ribeye is boneless and the rib steak, which is sometimes also called a bone-in ribeye or Delmonico steak, is not boneless. Other than that, both ribeye steak and rib steak are taken from the same cut of the beef and taste just the same.