Bryan Garner (see http://tinyurl.com/5k4too) may be the foremost exponent of effective legal writing but, as with all geniuses' proposals, some of Garner's are quixotic. Garner wants to revise legal citation and footnoting conventions by placing all citations in footnotes and abolishing content footnotes. The normative legal string-on cite interrupts the flow of text according to Garner, and usurps the stress role, occurring at a sentence's end. Content footnotes serve no legitimate function because if relevant the footnote’s content should integrate with the text, and if insufficiently relevant for textual integration, the parenthetical matter should be extirpated outright, not exiled to marginalia.
But legal citations often contain optional amplification, which the standard citation formats bracket at the end. The amplification succinctly shows how the case supports the author’s claim, quoting the case, paraphrasing it, or stating the holding in fact-specific terms. Optional for citation, the amplification is necessary for understanding, so placing the amplification in a footnote makes reading inefficient. In contrast, experienced attorneys adjust to the textual disruption, mitigating the grounds for Garner's objection to string-on cites.
Content footnotes provide a new bottom-most hierarchical level, where hierarchy is important for Clarity. A hierarchy of headings, numbering at least one and at most four, encases a brief and allows the reader to review the contentions at alternative levels of generality. A content footnote imparts information belonging to a hierarchical level one-step lower than body text. Footnotes should not be numerous, however, because Concision in a legal brief is too important to include subtextual detail. Content footnotes can answer the occasional frivolous argument that would be fatal if the court, improbably, adopts it. Responding to the yet unargued point in a footnote avoids granting the argument undeserved respectability.