What does infra mean, and how is it different from supra?
You keep seeing "see infra" in opinions and law-review articles, usually not far from its opposite, supra. What does each one point to? Can you use infra for a case you plan to cite later? And do any courts refuse both?
Reply below if your court or journal has its own rule on cross-references.
The team’s answer
Short answer. They are Latin for "below" (infra) and "above" (supra). Infra sends the reader forward to a later part of the same document. Supra can point backward the same way, but it has a second job that infra lacks: as a short form, it sends the reader back to a source you already cited in full. So infra is only ever a cross-reference. It can't replace a citation.
What each one does [Convention]
Infra, a forward pointer: "see infra Part IV."
Supra, a backward pointer: "see supra Part II."
Supra, a short form for a secondary source cited in full earlier: Holmes, supra, at 461.
If you rely on a case later in your paper, cite it in full at the point where you first rely on it. Don't send the reader ahead with infra.
How it looks in an opinion [Convention] Supreme Court opinions point to their own pages. In Loper Bright, Justice Kagan's dissent sends the reader back to the majority with ante and to her own earlier pages with supra. Her slip opinion reads "See ante, at 15–16; supra, at 19–20." In the U.S. Reports preliminary print, the same sentence reads "See ante, at 393; supra, at 466–467":
Loper Bright Enters. v. Raimondo, 603 U.S. 369, 469 (2024) (Kagan, J., dissenting).
The pointers changed because every page number changed. A page-number infra in your own work carries the same risk: any edit that moves pages can break it.
Not every court uses it [Jurisdiction-specific]
California's style manual tells opinion writers to use ante and post for earlier and later parts of an opinion, keeps supra for citations to an authority cited earlier, and notes that infra "is not often used" and should never be paired with ante. California Style Manual (4th ed. 2000).
[Requirement] In Iowa appellate briefs, neither word is allowed: "Use of 'supra' and 'infra' is not permitted." Iowa R. App. P. 6.904(2)(d).
In briefs and memos [House style]
Plain English works everywhere and survives reorganizing: "See Part III, below." Point to the heading readers will actually see, and check every cross-reference again after the last round of edits, when parts and pages tend to move.
Common mistakes
"See infra" for a case you haven't cited yet.
"Smith, infra": infra has no short-form use.
A page-number infra that went stale when the pages moved.
Any supra or infra at all in a brief to an Iowa appellate court.
Read more
The Short Forms chapter (its opening is free to read): https://citationcode.com/book/short-forms (opens in a new tab)
Iowa's citation rules for appellate briefs, with source and effective date: https://citationcode.com/court-rules/ia (opens in a new tab)
Paste a draft into the checker; it flags a supra that names a case cited earlier in the draft and suggests the national short form for that case instead: https://citationcode.com/checker (opens in a new tab)