How to write an explanatory parenthetical (and when cf. needs one)
What goes inside the parenthetical after a case: a participle, a quotation, a full sentence? Does it start with a capital letter and end with a period? And which signals call for one?
Reply below with a parenthetical you are unsure about (no client facts) and members can weigh in.
The team’s answer
Short answer. Tell the reader in a few words what the source did that matters to your sentence. Either start with a present participle (holding, explaining, noting, arguing) in lowercase with no closing period, or quote a complete sentence from the source with its capital and its period. After cf., add one every time.
The rules behind it
[Convention] A paraphrase begins in lowercase, usually with an -ing verb, and takes no period before the closing parenthesis.
[Convention] A quotation earns a capital and a final period only when it is, or reads as, a full sentence. A quoted fragment stays lowercase.
[Convention] The verb should match what the source did. A majority opinion holds; a dissent or a concurrence argues or explains. For a plurality, a verb such as noting or reasoning avoids overstating it. Writing "holding" for a dissent misstates the authority.
[Convention] Cf. always gets an explanation, because the reader cannot see an analogy from the citation alone. The same goes for but cf. With see also and see generally, one is recommended, and the further the source sits from your sentence, the more the parenthetical has to say.
Examples (each checked against its source)
A paraphrase of a holding:
Loper Bright Enters. v. Raimondo, 603 U.S. 369, 412–13 (2024) (overruling Chevron and holding that a court may not defer to an agency's reading of a statute just because the statute is ambiguous).
A quoted complete sentence, so a capital and a period:
Michigan v. EPA, 576 U.S. 743, 752 (2015) ("No regulation is 'appropriate' if it does significantly more harm than good.").
A short description, when the page you cite is a list of authorities: (collecting cases).
A verb matched to the opinion, as a Justice wrote it in Loper Bright:
At page 469, Justice Kagan's dissent cites Justice Alito's dissent in Wilkinson v. Garland after Cf., with "(noting, in the immigration context, that ...)". Not "holding," which fits: a dissent holds nothing.
When the Court departs from the convention [Unresolved]
Practice is not uniform. At page 443 of Loper Bright, Justice Gorsuch's concurrence cites Justice Scalia's separate opinion in Decker after cf. with no explanatory parenthetical, only the label for the kind of opinion; the sentence around it does the explaining. At page 469 the dissent quotes a complete sentence from a law review article in a parenthetical and leaves off the final period. In your own brief, the conventional form is the safer choice: a judge reading a bare cf. has to guess at your analogy.
Common mistakes
A paraphrase that opens with a capital or closes with a period inside the parenthesis.
"(holding ...)" after a dissent, a concurrence or a plurality.
A parenthetical that repeats your sentence instead of saying what the source adds.
A bare cf.
A long quotation where a six-word paraphrase would do.
Read more
The free video lesson on citation anatomy, including parentheticals and weak signals: https://citationcode.com/lessons/l02-anatomy (opens in a new tab)
The Anatomy chapter (its opening is free to read): https://citationcode.com/book/anatomy (opens in a new tab)