Defendants in a trademark infringement or dilution claim can assert basically two types of affirmative defenses:
Fair use; or
Fair use occurs when a descriptive mark is used in good faith for its primary, rather than secondary, meaning, and no consumer confusion is likely to result. So, for example, a cereal manufacturer may be able to describe its cereal as consisting of “all bran,” without infringing upon Kelloggs’ rights in the mark “All Bran.” Such a use is purely descriptive, and does not invoke the secondary meaning of the mark. Similarly, in one case, a court held that the defendant’s use of “fish fry” to describe a batter coating for fish was fair use and did not infringe upon the plaintiff’s mark “Fish-Fri.” Zatarain’s, Inc. v. Oak Grove Smokehouse, Inc., 698 F.2d 786 (5th Cir. 1983). Such uses are privileged because they use the terms only in their purely descriptive sense.
Some parodies of trademarks may be permissible if they are not too directly tied to commercial use. The basic idea here is that artistic and editorial parodies of trademarks serve a valuable critical function, and that this critical function is entitled to some degree of First Amendment protection. The courts have adopted different ways of incorporating such First Amendment interests into the analysis. For example, some courts have applied the general “likelihood of confusion” analysis, using the First Amendment as a factor in the analysis. Other courts have expressly balanced First Amendment considerations against the degree of likely confusion. Still other courts have held that the First Amendment effectively trumps trademark law, under certain circumstances. In general, however, the courts appear to be more sympathetic to the extent that parodies are less commercial, and less sympathetic to the extent that parodies involve commercial use of the mark.