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Dingduff Legal Citation Format

Organization
DingDuff
dingduff-legal-citation-format

Format legal citations in the style courts expect (briefs, motions, memoranda, pleadings). Use when drafting, inserting, or fixing a citation to a case, statute, constitution, regulation, rule, secondary source (treatise, law review, etc), or a same-matter filing — or when a draft needs signals (e.g. see, cf., but see), pincites, short forms (id./supra), string cites, explanatory parentheticals, or quotation formatting (block quotes, alterations, omissions). Trigger whenever the user is writing or revising a legal document that relies on authority and wants its citations to look right or when a citation looks malformed. Rules follow The Indigo Book. COVERS FORM ONLY: it does not verify that an authority exists, is good law, or is quoted accurately; pair it with primary-source verification (separate skill). NOTE: This skill and reference files are large, so run it in a subagent — delegate the formatting task rather than loading the full skill into the main context window. (v1.4)

Overview

PublisherDingDuff
Repositorydingduff-public
Skill namedingduff-legal-citation-format
Stars
63
Forks
8
Bundled files
6
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • 6 bundled files

    Scripts, templates, and references the model can read while it works. Files are read-only and never executed.

  • Open source

    Published by DingDuff on GitHub. Read the source before you install it.

Installation

Install the Dingduff Legal Citation Format AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/DingDuff/dingduff-public/tree/main/plugins/dingduff/skills/dingduff-legal-citation-format
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/DingDuff/dingduff-public.git /tmp/dingduff-public
mkdir -p .claude/skills
cp -r /tmp/dingduff-public/plugins/dingduff/skills/dingduff-legal-citation-format .claude/skills/dingduff-legal-citation-format
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Dingduff Legal Citation Format in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Dingduff Legal Citation Format on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Dingduff Legal Citation Format is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Legal Citation Format — Practitioner / Brief Style

This skill produces citations in the conventional practitioner format — the style used in standard legal documents (SLDs): documents filed with a court (briefs, motions, memoranda, pleadings) and documents lawyers write to one another or the public (opinion letters, legal memoranda). That format is intentionally simpler than the academic style used in law review articles (ALDs), and it is close enough to uniform across U.S. jurisdictions that one generic standard works for almost everything an attorney files. The rules below state the SLD form; where a law-review (ALD) convention differs, that is flagged.

Source and attribution

The rules and examples in this skill are based on, and written to be consistent with, The Indigo Book: A Manual of Legal Citation (Sprigman et al., Public Resource 2016) — a free, open-source implementation of the same Uniform System of Citation that The Bluebook implements. The Indigo Book is dedicated to the public domain under a CC0 dedication, and the citation system it restates ("a uniform system of citation") consists of facts and methods that no one owns. Where this skill addresses the consolidated "(cleaned up)" quotation parenthetical, it also follows the approach adopted in The Indigo Book's second edition (Romig et al., 2021/2022).

This skill is an original document, not a copy or reproduction of The Indigo Book. It restates and adapts the citation rules in our own words and with our own (illustrative) examples, for use in practice. The Indigo Book is not affiliated with or authorized by The Bluebook® A Uniform System of Citation®, and neither is this skill. Citations produced under this guide are compatible with the Uniform System of Citation. For any rule this skill does not reach, consult The Indigo Book (https://law.resource.org/pub/us/code/blue/IndigoBook.html) or a full citation manual.

Version 1.4 — reconciled with The Indigo Book.

Before anything else: defer to controlling local rules

A court's own rules, a standing order, or a jurisdiction-specific style manual always wins. Many courts modify citation form in small ways (preferred reporters, parallel-citation requirements, how record cites look, whether citations may sit in footnotes). When the user names a court or jurisdiction, follow its rules and treat the standard below only as the gap-filler. When nothing court-specific is in play, the generic format here is the safe default.

How practitioner style differs from academic style

This is the single most common source of "wrong-looking" citations, so internalize it:

  • Two typefaces, not three. Court documents use only ordinary roman type and italics (equivalently, underlining). The large-and-small-caps used in law review footnotes for author names and book/journal titles do not appear in a brief. An author's name and a journal name are set in ordinary roman.
  • Case names are italicized in citations and in text (academic style leaves them roman in the main text).
  • Citations live in the body text, immediately after the proposition they support — not in footnotes — unless local rules say otherwise.

Pick italics or underlining and use it consistently throughout the document. Italics is the modern default; some judges and older local practice prefer underlining. They are exact equivalents — never mix them in one document.

Workflow for any citation task

  1. Identify the authority type (case, statute, constitution, regulation, rule, legislative material, secondary source, or a filing in the same matter). Each has its own pattern — see the quick reference below and the linked reference files.
  2. Build the full citation the first time the authority appears.
  3. Switch to a short form for every later reference (see references/short-forms-and-quotations.md).
  4. Place the citation as a citation sentence or citation clause, add an introductory signal if the relationship isn't direct, and add an explanatory parenthetical if it helps (see references/signals-and-structure.md).
  5. Apply typeface rules — italicize what should be italicized (below), nothing more.
  6. Verify the details against the relevant reference file before finalizing — abbreviations, spacing, and punctuation are where citations most often go wrong.

When the task is to clean up an existing document, read the citations, diagnose each against these rules, and fix form without changing the substance (volume, page, court, year, quotation text).

What to italicize (court-document typeface)

Italicize (or underline):

  • Case names, including the v. and any procedural phrase that is part of the name (In re, Ex parte, ... ex rel. ...). The comma after the case name is roman, not italic.
  • Introductory signals (See, Cf., But see, e.g., etc.).
  • id., supra, infra, and similar cross-reference words.
  • Phrases introducing case history (aff'd, rev'd, cert. denied, sub nom., etc.).
  • Words introducing related authority (quoting, citing, quoted in).
  • Titles of books, articles, and other standalone works.
  • In running text: titles of periodicals, words that were italicized in the original of a quotation, and non-English words not in common English usage.

Do not italicize: reporter abbreviations, anything in a statute or constitution citation (nothing in those is italicized), court/jurisdiction abbreviations, or the publisher/date parenthetical.

Quick reference — the citations you build most often

These cover the large majority of brief cites. Full detail and edge cases are in the reference files.

Cases (full citation)

Pattern: <Case Name>, <Volume> <Reporter> <First Page>, <Pincite> (<Court> <Year>) (<parentheticals>)<, history>.

  • U.S. Supreme Court: Alvarez v. United States, 571 U.S. 320, 331 (2014).
  • Federal court of appeals: Vasquez v. Coastal Freight Co., 640 F.3d 200, 207 (9th Cir. 2011).
  • Federal district court: Okafor v. Summit Indus., Inc., 305 F. Supp. 3d 410, 418 (S.D. Tex. 2018).
  • State high court (regional reporter): Whitman v. Harbor Mut. Ins. Co., 431 P.3d 220, 224 (Cal. 2018).
  • State intermediate court: Marsh v. Cedar Valley Hosp., 215 S.W.3d 700, 705 (Tex. App. 2006).

(Party names, volumes, and pages in these examples are illustrative — they show form, not real cases.) Notes: the U.S. Supreme Court takes no court abbreviation — the year alone sits in the parenthetical. A state's highest court likewise takes no court name; include the state in the parenthetical when you cite a regional reporter, and give the year alone only when the official state reporter already names the state. A footnote pincite is , 226 n.4 with no space inside n.4. If the pincite is the first page of the opinion, repeat the page: 488 F.3d 415, 415. Where a state has adopted a public-domain (media-neutral) citation, The Indigo Book encourages using it, with a parallel cite to the regional reporter where possible (see references/cases.md).

Statutes

Pattern: <Title> <Code> § <Section> (<Year>).

  • Federal: 42 U.S.C. § 1983 (2018). Multiple sections: 29 U.S.C. §§ 201–219 (2018). Subsections: 17 U.S.C. § 106(1) (2018).
  • With the act's name: Securities Exchange Act of 1934 § 10(b), 15 U.S.C. § 78j(b) (2018).
  • State (unofficial code shows the publisher): Tex. Civ. Prac. & Rem. Code Ann. § 16.003 (West 2017); Cal. Civ. Code § 1542 (West 2019).
  • Federal rules (no date): Fed. R. Civ. P. 12(b)(6); Fed. R. Evid. 401.

Nothing in a statute cite is italicized. The year is the edition of the code, not the year of enactment. The official U.S. Code is recodified every six years (2000, 2006, 2012, 2018, …); cite the most recent edition that contains the version of the statute you mean, adding a supplement parenthetical if the provision was amended after that edition (e.g., (2018 & Supp. II 2020)). The Indigo Book includes the edition year; some attorneys and courts omit it for the current official Code, but include it when in doubt or when local rules expect it.

Constitutions

U.S. Const. art. I, § 8, cl. 3. U.S. Const. amend. XIV, § 1. U.S. Const. pmbl. State: Tex. Const. art. I, § 9. No date for a constitution still in force; nothing italicized.

Short forms

  • id. — points to the immediately preceding authority. Same page: Id. Different page: Id. at 100. Capitalize only when it begins a citation sentence; the period is part of it.
  • Case short form — distinctive party name + reporter + at + pincite: Whitman, 431 P.3d at 224. Choose the memorable party (not "United States," "State," "City of ___," or another common litigant).

That is enough for cases, statutes, and constitutions in most filings. For everything else, and for the rules behind the patterns above, use the reference files.

Reference files — read the one you need

  • references/cases.md — full case form in depth: case names (citation vs. textual sentences), reporters and which to cite, pincites and page ranges, court/jurisdiction, weight and explanatory parentheticals, prior/subsequent history, and unreported/electronic cases.
  • references/statutes-constitutions-regulations.md — federal and state statutes, session laws, named acts, constitutions, the C.F.R. and Federal Register, agency adjudications, executive orders, legislative materials (bills, reports, hearings), procedural rules, restatements, uniform acts, and tax materials.
  • references/secondary-sources.md — treatises and books, law review and journal articles, magazines and newspapers, encyclopedias, dictionaries, and documents filed in the same matter (record cites, briefs, motions, transcripts).
  • references/signals-and-structure.md — citation sentences vs. clauses, the full set of signals and what each means, the order of signals, the order of authorities within a citation, string citations, and explanatory parentheticals.
  • references/short-forms-and-quotations.md — id., supra, hereinafter, case short forms with parallel cites; inline vs. block quotations (50-word rule), alterations (brackets, [sic], added emphasis), omissions (ellipses), and how to collapse a pile-up of cleanup parentheticals into a single (cleaned up) — the convention this guide uses, consistent with The Indigo Book's second edition.
  • references/abbreviations.md — common reporters, federal and state court abbreviations and the spacing rules, case-name word abbreviations (including the few allowed in textual sentences), history/explanatory phrases, geographic terms, and months.

Mistakes to watch for

  • Using large-and-small-caps or leaving case names un-italicized (that's academic style, not brief style).
  • Italicizing the comma after a case name, or italicizing parts of a statute cite.
  • Adding a court abbreviation for a U.S. Supreme Court cite (the year stands alone).
  • Wrong reporter series for the court (e.g., a district-court opinion cited to the Federal Reporter instead of the Federal Supplement).
  • Spacing in court/reporter abbreviations: close up adjacent single capitals (S.D.N.Y.), but space a single capital from a longer abbreviation (D. Mass., S.D. Cal.).
  • Dropping the pincite — a brief should point the reader to the exact page, not just the opinion's first page.
  • Beginning a quotation with an ellipsis, or forgetting that a sentence-ending omission keeps the sentence's final period (four dots total).
  • Forgetting to switch to a short form after the first full citation, or using id. when the immediately preceding citation was to a different authority.

Bundled files

The model reads these on demand while the skill is loaded. They are exposed as readable files and are never executed.

Frequently asked questions

What does the Dingduff Legal Citation Format AI skill do?

Format legal citations in the style courts expect (briefs, motions, memoranda, pleadings). Use when drafting, inserting, or fixing a citation to a case, statute, constitution, regulation, rule, secondary source (treatise, law review, etc), or a same-matter filing — or when a draft needs signals (e.g. see, cf., but see), pincites, short forms (id./supra), string cites, explanatory parentheticals, or quotation formatting (block quotes, alterations, omissions). Trigger whenever the user is writing or revising a legal document that relies on authority and wants its citations to look right or wh...

Why use Dingduff Legal Citation Format on TypingMind?

Because you install it once and use it with any model. Dingduff Legal Citation Format is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Dingduff Legal Citation Format in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/DingDuff/dingduff-public/tree/main/plugins/dingduff/skills/dingduff-legal-citation-format. TypingMind reads its SKILL.md and bundles its files and installs it as a skill you can enable per chat.

Which AI models can use Dingduff Legal Citation Format?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Dingduff Legal Citation Format?

As many as you like. As long as a model supports skills, you can use Dingduff Legal Citation Format with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Dingduff Legal Citation Format AI skill free?

It is published on GitHub by DingDuff. Check the repository for licensing terms. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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