sentences:  To promote continuing interest in the product, Burger King occasionally releases limited-time (LTO) variants in the line that have different toppings or ingredients such as ham, Italian sausage or pulled pork.Being one of the company's major offerings, the Specialty Sandwiches are sometimes the center of product advertising for the company.Despite being a major product line in the company's portfolio, Burger King has registered very few global trademarks to protect its investment in the products.