---

name: bluebook description: This skill should be used when the user asks to "cite a case", "format a citation", "check Bluebook format", "cite a statute", "use id. or supra", "format footnotes", "cite a law review article", or needs Bluebook 21st Edition citation guidance. Covers cases, statutes, secondary sources, signals, and short forms.

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:

1. Verify case name spelling and procedural posture
2. Verify reporter volume and page numbers
3. Verify court and year
4. Verify pinpoint page exists

Guessing reporter volumes or page numbers is LYING. Period.

Id., supra, and hereinafter REQUIRE a preceding full citation.

Before using ANY short form:

1. Locate the full citation in the document
2. Verify no intervening citations (for id.)
3. Verify the supra reference is unambiguous

Using id. after intervening citations creates ambiguity. Delete and cite in full.

Law review citations use footnote format (Rule 1). Court documents use text format (Bluepages).

CopyFOOTNOTE (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.

The Gate Function

Before writing ANY citation:

Copy1. 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.

Rationalization Table - STOP If You Think:

Red Flags - STOP Immediately If:

• "Let me guess the reporter volume" → NO. Verify the actual cite.
• "Id. probably works here" → NO. Check for intervening citations.
• "Supra will point them back" → NO. Verify the full citation exists.
• "I'll use the common abbreviation" → NO. Use Bluebook tables.
• "Close enough on the page number" → NO. Exact pinpoints required.

Quick Reference: Common Citation Forms

Cases (Rule 10)

CopyFull 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)

CopyFull 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)

CopyFull 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)

CopyFull citation:
Richard A. Posner, Economic Analysis of Law 45 (9th ed. 2014).

Short form:
Posner, supra note 5, at 52.

Typeface Rules (Rule 2)

Introductory Signals (Rule 1.2)

Signal Order (Rule 1.3)

Within a single citation sentence, signals appear in this order:

1. [no signal]
2. E.g.,
3. Accord
4. See
5. See also
6. Cf.
7. Compare
8. Contra
9. But see
10. But cf.
11. 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)

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:

1. /bluebook formats citations correctly
2. /writing-legal ensures argument structure and evidence handling
3. /ai-anti-patterns catches AI writing indicators before submission

Delete & Restart Pattern

When to delete and restart:

1. Citation uses guessed page numbers → Delete, verify source, cite with real numbers
2. Id. follows intervening citation → Delete id., use full short form
3. Wrong signal used → Delete, reread Rule 1.2, apply correct signal
4. Typeface incorrect → Delete, apply Rule 2 typeface
5. Abbreviation doesn't match Bluebook tables → Delete, use table abbreviation

How to restart:

CopyOld: 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.