There are at least two good reasons why appellate lawyers should mostly avoid using footnotes in briefs. First, if what you’re saying is important, relegating it to a footnote could waive its status as legal argument, meaning that the court need not even consider the argument. In May 2019, the Massachusetts Appeals Court discussed this point in a zoning case involving a statute of repose applied to a structure. See Barkan v. Zoning Board of Appeals of Truro, No. 18-P-365 (May 30, 2019). The trial judge ruled that the plaintiffs' action was untimely principally because they failed to bring a judicial challenge to the 2008 issuance of a building permit, he ruled the action also was untimely because the plaintiffs did not commence it within the six-year limitations period that began to run on the "commencement of the alleged violation" (which -- according to the judge -- was the date that the invalid permit issued). G. L. c. 40A, § 7. But the Appeals Court noted that “the only discussion of this alternative ground anywhere in the plaintiffs' forty-nine page opening appellate brief is in a single footnote.” It further cited Boston Edison Co. v. Massachusetts Water Resources Auth., 459 Mass. 724, 727 n.3 (2011), for the proposition that “arguments relegated to a footnote do not rise to the level of appellate argument.”
A second reason to mostly avoid footnotes is that many appellate judges have for years now principally read briefs on electronic tablets. Anyone who has spent much time trying to read briefs or decisions on electronic tablets realizes that it’s awkward to move and down through a document in that format. Functionally, it simply works better and reads more fluidly to keep things in a single-flow narrative. Imagine trying to read The Great Gatsby if 20 percent of the story was in footnotes. And make no mistake, appellate briefs should read like literature. The best ones persuade, in part, with writing that’s compelling.