United States trademark law includes a “trademark fair use” defense to distinguish it from the fair use doctrine used in copyright law. “The ‘fair use’ defense forbids a trademark registrant to appropriate a descriptive term for his/her exclusive use and so prevent others from accurately describing a characteristic of their goods” [Soweco, Inc. v. Ohell Oil Co., 617 F.2d 1178, 1185 (5th Cir. 1980)].
A court must determine whether a trademark use is an infringement, or whether it is strictly a descriptive or informative fair use. A defendant asserting the fair use affirmative defense need only prove that it is not using the term as a mark, but rather as a fair and good faith description of the good attached to it [15 USC 1115(b)(4)].