Citations are the shorthand that lets lawyers, courts, and researchers point to one specific judicial decision. A citation crowds a remarkable amount of information into a short string: the parties, the deciding court, where the opinion is printed, the page it begins on, and the year of decision. Learn the pattern, and entries like 410 U.S. 113 (1973) or 202 F.3d 660 (5th Cir. 2000) stop resembling code and start reading like an address.
What a Citation Accomplishes
A citation performs three jobs. It pins down a unique decision so it can't be confused with a similar case. It names the court that ruled, which signals how much weight the decision carries. And it gives a path to the full opinion so a reader can verify whether the citing party described it accurately. In legal writing, a proposition of law with no citation is merely an assertion. Add a citation, and it becomes checkable.
The Core Structure
Most case citations run in the same order: parties, reporter, volume, page, court, year. Consider Brown v. Board of Education, 347 U.S. 483 (1954). The parties are Brown and the Board of Education. U.S. is the reporter, the official series of volumes for the United States Reports. The number 347 is the volume, and 483 is the opinion's first page. The parenthetical year, 1954, is the year the decision issued.
Some citations add a court abbreviation when the reporter serves more than one court, and many add parallel citations to a second reporter. A longer citation may look like Smith v. Jones, 123 F.3d 456, 459 (9th Cir. 1997), where 459 is a pin cite to the exact page and (9th Cir. 1997) names the court and year.
Reporters for Federal Courts
| Reporter | Court | Notes |
|---|---|---|
| U.S. | U.S. Supreme Court | Official United States Reports |
| S. Ct. | U.S. Supreme Court | Unofficial, faster to publish |
| L. Ed. 2d | U.S. Supreme Court | Unofficial, includes summaries |
| F., F.2d, F.3d, F.4th | U.S. Courts of Appeals | Numbered series mark the era |
| F. Supp., F. Supp. 2d, F. Supp. 3d | U.S. District Courts | Trial-level federal decisions |
| F. App'x | U.S. Courts of Appeals | Unpublished dispositions with limited authority |
| B.R. | Bankruptcy Courts | Bankruptcy Reporter |
The series numbers carry meaning. When a reporter fills up, the publisher begins a new series, so F.2d follows F. and F.3d follows F.2d. Drop the series, and you may cite the wrong volume.
State and Regional Case Reporters
State supreme court and appellate decisions show up in two places. Official state reporters carry names like Cal. 2d, N.Y.2d, or Ill. 2d. Regional reporters group several states into one series, including A.2d and A.3d (Atlantic), P.2d and P.3d (Pacific), N.E.2d (Northeastern), N.W.2d (Northwestern), S.E.2d (Southeastern), So. 2d and So. 3d (Southern), and S.W.2d and S.W.3d (Southwestern). A number of states have discontinued official reporters and now depend on the regional series plus neutral citations.
Decoding the Court Parenthetical
The parenthetical reveals which court decided the case. (9th Cir. 2018) is the Ninth Circuit Court of Appeals. (S.D.N.Y. 2019) is the Southern District of New York, a federal trial court. (Tex. 2020) is the Texas Supreme Court. Without that parenthetical, a reader can't tell whether a ruling came from a trial court, an intermediate appellate court, or a court of last resort, which affects how much authority it carries.
Pin Cites, Signals, and Shorthand
A pin cite points to a specific page: 347 U.S. at 495. Signals such as see, see also, cf., and e.g. show how the cited authority relates to the proposition. After the first full citation, writers switch to a short form: Brown, 347 U.S. at 491, or id. at 495 when the reference is to the authority immediately preceding. The id. form is fragile because it breaks if the preceding citation changes, so read it as a pointer to the sentence just before it.
Tracking Subsequent History
Opinions don't always stay as issued. A later development appears as subsequent history: aff'd (affirmed), rev'd (reversed), vacated, cert. denied (the Supreme Court declined review), overruled by, or abrogated by. Overlooking subsequent history ranks among the most common research errors. A case that was good law when decided may have been narrowed or eliminated later, and a citation that stops at the original decision can mislead.
Slip and Unpublished Opinions
Not every decision lands in a printed reporter. Courts issue slip opinions first, often carrying docket numbers such as No. 21-1234, and some dispositions are marked not for publication. Unpublished federal appellate decisions may not be citable as precedent in some circuits, or may be citable only for persuasive value. Always check the court's local rules before relying on one.
Finding the Full Opinion
Free options have improved enormously. CourtListener at courtlistener.com hosts millions of opinions and includes citator-style signals. Google Scholar covers many state and federal cases. GovInfo at govinfo.gov publishes official federal materials, and individual court websites post recent opinions. PACER at pacer.uscourts.gov remains the source for federal docket sheets and filings. For state cases, the state judiciary website is frequently the fastest official source.
Reading Citations With Care
Two final habits help. First, check whether the citing document quoted the case or merely cited it, because a citation can support a narrow point while implying broader agreement. Second, confirm the case is still good law by looking for later treatment. Citations are a map, not the destination. The reasoning lives in the opinion itself.
This guide is general information about legal research, not legal advice. Citation formats and local rules vary, and readers should verify authority against official sources.