Artifacts from the family of Col. Harland Sanders contained fried chicken recipes, but KFC has insisted the one with the correct 11 herbs and spices is kept secure in its headquarters.

KFC claims that Church's use of the phrase "original recipe" in its own advertisements "is likely to create confusion in the marketplace.

KFC is taking one of its smaller rivals to court, suing Church's Texas Chicken for allegedly violating its trademark rights by using the phrase "Original Recipe" in pitching its fried poultry products.

In a lawsuit filed Nov. 8 in the U.S. District Court for the Eastern District of Texas, KFC has accused fellow fast-food fried chicken purveyor Church's Texas Chicken of violating its trademark rights by using the phrase "Original Recipe" in its advertisements and promotions.

Church's Chicken has recently begun advertising some new chicken, bragging about the fact that they've gone back to the "original recipe." This is famously what KFC calls its fried chicken, in reference to Harland Sanders' original recipe.

KFC’s “Original Recipe” trademark, which it says is a secret blend of 11 herbs and spices, has long been part of the company’s branding. The blend is closely guarded, and the company calls it one of the most “iconic trade secrets in the food industry.” It first trademarked the phrase in 1984.

KFC has filed a lawsuit against Church's Texas Chicken for allegedly violating its trademark rights by using the term "original recipe" in its advertising.