The Bluebook
title-case rules
For legal citation, case names, law reviews.
The Bluebook rules
The Bluebook: A Uniform System of Citation (21st ed.) is the legal-citation standard used by U.S. courts, law firms, and law reviews. Its title-case rule — Rule 8 in the main volume, restated as B8 in the Bluepages for practitioner documents — governs article titles, book titles, and headings.
- Capitalize the first word and the word after a colon.
- Capitalize all words except articles, conjunctions of four or fewer letters, and prepositions of four or fewer letters.
- Lowercase short articles, conjunctions, and prepositions of four letters or fewer in the middle of a title.
- Always capitalize five-letter-or-longer prepositions (Between, Among, Without, Through).
What Rule 8 does not cover
The most common mistake isn't a capitalization error — it's applying Rule 8 to the wrong kind of text. Rule 8 governs titles (articles, books, headings). It does not govern:
- Case names — these follow Rule 10 (or B10 in the Bluepages), which is ordinary sentence capitalization for party names, not title case.
United States v. Nixon, notUnited States V. Nixon. The abbreviation "v." is always lowercase and always abbreviated — never "vs." or "versus" in a citation. - Statutory and regulatory titles — Rules 12 and 14 have their own conventions for acts, codes, and administrative materials.
- Court and party designations — "Court" is capitalized when referring to the specific court a document is filed in, per B8, independent of title case.
This tool applies Rule 8 title case to whatever you paste — it's built for article titles, book titles, and headings, not for auto-formatting case names or statutory citations.
Italics
Bluebook article titles and book titles are conventionally set in italics within a citation. This converter handles capitalization only — once you copy the title-cased output into your citation, apply italics separately, since plain text can't carry that formatting through a copy-paste.
Worked examples
The same set of titles, converted under The Bluebook rules. Try them yourself by switching the style pill on the homepage.
| Input | Bluebook |
|---|---|
a treatise on the law of contracts |
A Treatise on the Law of Contracts |
the rule against perpetuities |
The Rule Against Perpetuities |
commercial paper and the uniform commercial code |
Commercial Paper and the Uniform Commercial Code |
tort liability in the modern era |
Tort Liability in the Modern Era |
Edge cases we handle
- Proper nouns — iPhone, JavaScript, NASA stay capitalized correctly mid-title.
- Hyphenated compounds — handled per Bluebook's specific rule.
- After a colon — the first word after a colon is capitalized.
- Acronyms and ALLCAPS runs — preserved as-is.
Bluebook vs. Chicago vs. AP
| Style | Minor-word cutoff | Governs case names? |
|---|---|---|
| Bluebook | ≤4 letters | No — Rule 10 instead |
| Chicago | All lengths (unless adverbial) | Not applicable |
| AP | ≤3 letters | Not applicable |
Chicago actually lowercases every preposition regardless of length — a broader rule than Bluebook's four-letter cutoff, so a word like "Without" stays lowercase under Chicago but gets capitalized under Bluebook. The other key difference is scope: Bluebook has dedicated rules for case names, statutes, and court documents that Chicago simply doesn't address.
Frequently asked questions
Does Bluebook title case apply to case names?
No. Case names like United States v. Nixon follow Rule 10, not Rule 8. They use ordinary sentence capitalization for party names, and "v." is always lowercase and abbreviated — never "vs."
Are Bluebook titles italicized?
Yes, article and book titles are conventionally italicized in citations. This tool handles capitalization only; apply italics after copying the result.
What's the letter-count cutoff for Bluebook prepositions?
Four letters or fewer stay lowercase mid-title (from, with, over). Five-letter-or-longer prepositions (Between, Among, Without) are always capitalized.
How is Bluebook different from Chicago in practice?
Chicago lowercases prepositions of any length, while Bluebook only lowercases prepositions of four letters or fewer. On a title with a longer preposition like "Without" or "Between," the two styles disagree. Bluebook also has separate, dedicated rules for case names, statutes, and court filings that Chicago doesn't cover at all.
How do you format legal titles using Bluebook rules?
Article and book titles follow Rule 8 (the title-case rule on this page). Case names follow the completely different Rule 10 — ordinary proper-noun capitalization joined by a lowercase "v." Statutes and regulations follow Rules 12 and 14.
Try Bluebook title case now.
Open the converter →Sources
This page summarizes public guidance from The Bluebook: A Uniform System of Citation. For the complete, authoritative rules, consult the official source directly:
- The Bluebook — the official, subscription-based reference published by the Harvard Law Review Association, compiled with the Columbia Law Review, University of Pennsylvania Law Review, and Yale Law Journal
- Cornell Legal Information Institute — Introduction to Basic Legal Citation — a freely accessible companion reference, indexed to The Bluebook
Want to compare with another style? See the style guides index. Formatting a case name rather than an article title? Read the case-name exception everyone misses.