Bluebook 21st Edition Citation
Citation formatting for law reviews and legal scholarship per The Bluebook: A Uniform System of Citation (21st ed. 2020).
Announce: “I’m using the bluebook skill for citation formatting.”
When to Use
Invoke this skill for:
- Formatting case citations (federal, state, foreign)
- Statutory and regulatory citations
- Secondary sources (books, articles, treatises)
- Short form citations (id., supra, hereinafter)
- Introductory signals and parentheticals
- Citation sentences vs. citation clauses
For legal writing style: Use /writing-legal skill (Volokh)
For general writing: Use /writing skill (Strunk & White)
If you haven’t verified EVERY element of a citation, DO NOT write it.
Before writing ANY citation:
- Verify case name spelling and procedural posture
- Verify reporter volume and page numbers
- Verify court and year
- Verify pinpoint page exists
Guessing reporter volumes or page numbers is NOT HELPFUL — the user publishes with wrong citations that fail verification. Period. </EXTREMELY-IMPORTANT>
<EXTREMELY-IMPORTANT> ## IRON LAW #2: NO SHORT FORMS WITHOUT FULL CITATION FIRSTId., supra, and hereinafter REQUIRE a preceding full citation.
Before using ANY short form:
- Locate the full citation in the document
- Verify no intervening citations (for id.)
- Verify the supra reference is unambiguous
Using id. after intervening citations creates ambiguity. Delete and cite in full. </EXTREMELY-IMPORTANT>
<EXTREMELY-IMPORTANT> ## IRON LAW #3: FOOTNOTE VS. TEXT CITATION FORMATLaw review citations use footnote format (Rule 1). Court documents use text format (Bluepages).
FOOTNOTE (law reviews): Smith v. Jones, 500 U.S. 1, 5 (1991).
TEXT (court documents): Smith v. Jones, 500 U.S. 1, 5 (1991)
FOOTNOTE (statutes): 18 U.S.C. § 1001 (2018).
TEXT (statutes): 18 U.S.C. § 1001 (2018)
If writing for a law review and using text format conventions, DELETE and reformat. </EXTREMELY-IMPORTANT>
The Gate Function
Before writing ANY citation:
1. IDENTIFY → What type of source? (case, statute, article, book)
2. LOCATE → Find the correct rule in Bluebook
3. VERIFY → Confirm ALL elements (volume, page, court, year)
4. FORMAT → Apply correct typeface and punctuation
5. CHECK → Does this match examples in the rule?
6. WRITE → Only after steps 1-5
Skipping any step produces unreliable citations.
Citation Facts
- An intervening citation breaks id. — id. after an intervening cite is ambiguous and must become a full short form. Supra only works when the full citation it points to actually exists earlier in the document.
- Signals are checked against Rule 1.2 examples, not intuition — a wrong signal misleads the reader about how the source supports the proposition.
- Parentheticals explain the source's relevance; pinpoints prove the specific claim. A cite deferred ("I'll add the pinpoint later") ships without one.
- Typeface (Rule 2) is mandatory, not stylistic. Abbreviations come from tables T6, T10, T12 — "common" or "obvious" abbreviations that don't match the tables fail cite-check.
- "Pretty sure" about a reporter volume or page number means unverified — a guessed element presented as a citation is an unverified claim, and exact pinpoints are required.
Quick Reference: Common Citation Forms
Cases (Rule 10)
Full citation:
Brown v. Board of Education, 347 U.S. 483, 495 (1954).
Short form (same footnote or five footnotes with no intervening):
Id. at 496.
Short form (different footnote, no intervening):
Brown, 347 U.S. at 497.
Short form (intervening citations):
Brown v. Board of Education, 347 U.S. at 498.
Statutes (Rule 12)
Full citation:
42 U.S.C. § 1983 (2018).
Multiple sections:
42 U.S.C. §§ 1983-1985 (2018).
Short form:
§ 1983 or id. § 1984
Law Review Articles (Rule 16)
Full citation:
Cass R. Sunstein, *On the Expressive Function of Law*, 144 U. Pa. L. Rev. 2021, 2030 (1996).
Short form:
Sunstein, supra note 12, at 2035.
Books (Rule 15)
Full citation:
Richard A. Posner, Economic Analysis of Law 45 (9th ed. 2014).
Short form:
Posner, supra note 5, at 52.
Typeface Rules (Rule 2)
| Source Type | Law Review Format | |-------------|-------------------| | Case names | Italics: Brown v. Board | | Book titles | Small caps: ECONOMIC ANALYSIS OF LAW | | Article titles | Italics: On the Expressive Function | | Journal names | Small caps: U. PA. L. REV. | | Periodical names (non-consecutively paginated) | Italics: N.Y. Times | | Statutes | Roman: 42 U.S.C. § 1983 |
Introductory Signals (Rule 1.2)
| Signal | Meaning | Use When | |--------|---------|----------| | [no signal] | Direct support | Source directly states proposition | | See | Implicit support | Source supports but doesn’t directly state | | See, e.g., | One of several | Multiple sources support; citing representative | | Cf. | Analogous support | Source supports by analogy | | Compare ... with | Comparison | Sources illustrate through contrast | | See generally | Background | Source provides helpful background | | But see | Contradiction | Source contradicts proposition | | Contra | Direct contradiction | Source directly contradicts |
Signal Order (Rule 1.3)
Within a single citation sentence, signals appear in this order:
- [no signal]
- E.g.,
- Accord
- See
- See also
- Cf.
- Compare
- Contra
- But see
- But cf.
- See generally
Common Errors Checklist
Case Citations
- [ ] Party names shortened properly (omit “Inc.”, “Ltd.” unless only identifier)
- [ ] “United States” abbreviated to “U.S.” (as party, not “United States of America”)
- [ ] Reporter abbreviation matches T1
- [ ] Court identifier included unless obvious from reporter
- [ ] Year is decision year, not argument year
- [ ] Pinpoint included for specific propositions
Statutory Citations
- [ ] Current official code used (not session laws for current statutes)
- [ ] Section symbol (§) used, not “Section”
- [ ] Space between § and number
- [ ] Year is code edition year, not enactment year
- [ ] Supplements cited when applicable
Short Forms
- [ ] Full citation appears earlier in same document
- [ ] Id. used only when no intervening citation
- [ ] Supra refers to footnote number where full cite appears
- [ ] Hereinafter defined in first full citation
Progressive Disclosure
For detailed rules, consult:
Reference Files
references/cases.md- Complete case citation rules (R. 10)references/statutes.md- Statutory and regulatory citations (R. 12-14)references/secondary-sources.md- Books, articles, treatises (R. 15-17)references/short-forms.md- Id., supra, hereinafter rules (R. 4)references/signals-parentheticals.md- Signals, parentheticals, order (R. 1)references/audit-patterns.md- Citation audit patterns and validationreferences/abbreviations.md- Bluebook abbreviation tables
NotebookLM Integration
For edge cases, ambiguous rules, or additional context beyond the reference files, query the Bluebook 21e (2020) notebook:
# Notebook ID: f70a9976-b443-43d5-b5fd-43ff86b2b700
# Query specific Bluebook rules
/Users/vwh7mb/projects/nlm/nlm generate-chat f70a9976-b443-43d5-b5fd-43ff86b2b700 “How do I cite an unpublished opinion under Rule 10.8.1?”
# Get rule clarification
/Users/vwh7mb/projects/nlm/nlm generate-chat f70a9976-b443-43d5-b5fd-43ff86b2b700 “What are the typeface conventions for treaty citations?”
# Verify abbreviation tables
/Users/vwh7mb/projects/nlm/nlm generate-chat f70a9976-b443-43d5-b5fd-43ff86b2b700 “What is the correct abbreviation for ‘Environmental’ in journal names per Table T13?”
When to query the notebook:
- Rule wording is ambiguous in reference files
- Formatting international or specialized materials
- Checking obscure abbreviations not in quick reference
- Resolving conflicts between rules
- Understanding historical changes from previous editions
When to Load References
Load the specific reference when:
- Formatting an unfamiliar source type
- Encountering edge cases (unpublished cases, foreign sources)
- Checking state-specific reporter requirements
- Working with complex statutory schemes
- Formatting international materials
Integration
Use with /writing-legal for complete legal scholarship workflow:
/bluebookformats citations correctly/writing-legalensures argument structure and evidence handling/ai-anti-patternscatches AI writing indicators before submission
Delete & Restart Pattern
When to delete and restart:
- Citation uses guessed page numbers → Delete, verify source, cite with real numbers
- Id. follows intervening citation → Delete id., use full short form
- Wrong signal used → Delete, reread Rule 1.2, apply correct signal
- Typeface incorrect → Delete, apply Rule 2 typeface
- Abbreviation doesn’t match Bluebook tables → Delete, use table abbreviation
How to restart:
Old: See Smith v. Jones, 500 U.S. at 15. Id. at 20. [intervening cite] Id. at 25.
New: See Smith v. Jones, 500 U.S. at 15. Id. at 20. [intervening cite] Smith, 500 U.S. at 25.
The third cite cannot use id. after an intervening citation.