Only meat cuts from the front half of the animal are commonly sold as kosher, because of the difficulty involved in removing the non-kosher veins of fat from the hindquarters. However, some of these kosher meat cuts are often labeled with the standard names for non-kosher meat cuts, such as "London Broil" or "spare ribs." These cuts are somewhat similar to the non-kosher ones, and are labeled in this way for the convenience of consumers. Before buying these cuts of meat, make sure the cut comes only from the front part of the animal and has been prepared by a reliable butcher under competent kosher supervision.
The term "Glatt Kosher" refers to meat which comes from a kosher, properly slaughtered animal which, upon its examination after the slaughtering, has been found completely free of any imperfections in the lungs. Simply "kosher" is when some of these imperfections are found but were declared permissible.
If you plan to kosher the meat or chicken in your home, your butcher must tell you the exact time of slaughtering so that you will be able to kosher the meat within 72 hours of that time.