Tacking Trademarks.

Rights to a trademark are determined by the date of the mark’s first use in commerce. The party who first uses a mark in commerce is said to have priority over other users. In limited circumstances, a party may modify its mark and still maintain its priority position, a doctrine known as tacking. The United States Supreme Court held that whether there has been tacking is a question for the jury, stating: “Because the tacking inquiry operates from the perspective of an ordinary purchaser or consumer, we hold that a jury should make this determination.” (Hana Fin., Inc. v. Hana Bank (U. S. Sup. Ct.; January 21, 2015) ___U.S.___ , [135 S.Ct. 907, 190 L.Ed.2d 800].)