The punctuation and trademark symbol are part of the name—and Kern's Kitchen, the bakery that invented Derby-Pie®, has sued enterprises as diverse as PBS and Bon Appetit magazine for using the pie's name to refer to similar chocolate-nut confections. Kern's even sued Nestle, its own chocolate chip supplier, for refusing to recall what Kern's lawyers called ''hundreds of thousands of infringing chocolate chip packages'' that bore a recipe for ''Tollhouse Derby Pie''. (Kern's eventually won all its lawsuits, so we're using that ®.) When the folks at Kern's eat out locally, they'll ask about chocolate-nut desserts, and should a waiter describe one as being ''like Derby Pie'', they'll complain. The result is that most Louisville eateries now call their pies by other, noninfringing, names, such as Triple Crown Pie, Winner's Circle Pie, or even—yuck!—Horse Race Pie.