Bluebook Short Form Citations: Id., Supra, and Shortened Forms Explained

Bluebook short form citations are one of the most confusing topics for first-year law students. When should you use "id."? When do you use "supra"? Why can "supra" be used for books but not for cases? And how does "hereinafter" work? The rules are scattered across Rule 4 and Rules 10.9, 12.10, 15.10, and 16.9 depending on the source type, and every subsection has its own quirks. This guide puts all the short-form rules in one place, with worked examples showing a complete footnote sequence so you can see exactly how the forms chain together in real legal writing.

If you want a quick automated citation instead of manually managing short forms, you can use the AllCitations Bluebook generator to format any case or statute. But short forms are something you must handle yourself because they depend on the structure of your document. This guide will make that easier.

Why Short Forms Exist

Legal writing cites the same authorities repeatedly. A law review article on equal protection might cite Brown v. Board of Education thirty times across its footnotes. Writing out the full citation every time would be repetitive and waste space. Short forms let you refer to an earlier citation concisely while still giving readers enough information to locate the source.

Bluebook short forms come in three main flavors:

1. Id. for immediately preceding citations
2. Shortened case names with "at" for non-adjacent case citations
3. Supra for non-case authorities like books, articles, legislative materials, and administrative sources

Each has its own rules, and mixing them up is one of the most common Bluebook errors that will show up on red-pen edits from your law review editor or clerking supervisor.

Id.: The Immediately Preceding Source

"Id." (italicized, including the period after it) means "the same" and is used to cite the same source as the immediately preceding footnote. Bluebook Rule 4.1 governs its use. The key requirement is that nothing else has been cited between the current footnote and the one you are referring to.

Basic Id. Usage

The simplest case is when two consecutive footnotes cite the exact same page of the same source.

1. Brown v. Board of Education, 347 U.S. 483, 495 (1954). 2. Id.

Footnote 2 means "the same source as footnote 1, same page." No further information is needed.

Id. at [Page] for a Different Page

When you want to refer to the same source but a different page, use "Id. at [page]".

1. Brown v. Board of Education, 347 U.S. 483, 495 (1954). 2. Id. at 498.

Footnote 2 means "the same source as footnote 1, now at page 498." The "at" is not italicized; only "Id." and the period after it are italicized.

When Id. Does Not Work

You cannot use "Id." if any other source has been cited in between, even in the same footnote. If footnote 1 cites Brown, footnote 2 cites Plessy v. Ferguson, and footnote 3 wants to cite Brown again, footnote 3 must use the shortened case name form, not "Id.". You also cannot use "Id." when the preceding citation had multiple sources unless you are referring to the last one.

1. Brown v. Board of Education, 347 U.S. 483, 495 (1954). 2. Plessy v. Ferguson, 163 U.S. 537, 544 (1896). 3. Brown, 347 U.S. at 495. [Cannot use Id. because Plessy was cited in footnote 2]

Shortened Case Names: Cases Only

For cases that were cited earlier in the document but not in the immediately preceding footnote, Bluebook Rule 10.9 requires a shortened case name with pin cite, not "supra".

The Shortened Form

The shortened form for cases uses: Shortened Case Name, Volume Reporter at Pin Cite.

15. Brown, 347 U.S. at 495.

"Brown" is the shortened case name, 347 is the volume, U.S. is the reporter, and 495 is the pin cite. Note the use of "at" before the pin cite, which is required for short forms but not for full citations.

Which Party to Use for the Short Name

The shortened case name usually uses the first party, but Bluebook Rule 10.9(a) says to use "the party whose name is more readily recognizable" when the first party is a common name (like "United States", "Commissioner", or "In re").

• Brown v. Board of Education becomes Brown
• United States v. Nixon becomes Nixon (not United States, which would be ambiguous)
• Commissioner v. Glenshaw Glass Co. becomes Glenshaw Glass (not Commissioner)

This means you must use judgment when choosing the shortened form, especially in cases involving the government as a party.

Shortened Forms vs. Id.

Use "Id." only when the previous footnote cited the exact same case and no other source intervened. Otherwise, use the shortened case name.

1. Brown v. Board of Education, 347 U.S. 483, 495 (1954). 2. Id. at 498. [Previous was also Brown, use Id.] 3. Plessy v. Ferguson, 163 U.S. 537 (1896). 4. Brown, 347 U.S. at 500. [Cannot use Id. because Plessy intervened]

Supra: Non-Case Authorities Only

"Supra" (italicized) means "above" and is used to refer back to earlier citations of non-case authorities: books, law review articles, legislative materials, treatises, and some government documents. Bluebook Rule 4.2 governs supra usage, with source-specific rules in Rules 15.10 (books), 16.9 (articles), and 13.7 (legislative materials).

The Supra Format

The supra format includes the author, a comma, "supra", the word "note", and the footnote number of the full citation.

10. Lawrence Lessig, Code: Version 2.0 (2006). 15. Lessig, supra note 10, at 45.

Footnote 15 refers back to the Lessig book cited in footnote 10, now pointing to page 45. The "at 45" is the pin cite for this subsequent reference.

Supra for Articles

For law review articles, supra uses the author and a shortened title if needed.

12. Cass R. Sunstein, Incompletely Theorized Agreements, 108 Harv. L. Rev. 1733, 1739 (1995). 20. Sunstein, supra note 12, at 1745.

Supra for Legislative Materials

Legislative materials like hearings and committee reports also use supra.

8. H.R. Rep. No. 103-518, at 5 (1994). 22. H.R. Rep. No. 103-518, supra note 8, at 7.

The Critical Rule: Never Use Supra for Cases

This is the Bluebook rule that confuses most 1L students. "Supra" is for books, articles, legislative materials, and similar non-case authorities. It is NOT for cases, statutes, regulations, or administrative decisions. For those source types, use the appropriate short form from their specific rules.

Wrong: Brown, supra note 3, at 495. Right: Brown, 347 U.S. at 495.

Wrong: 42 U.S.C., supra note 8, § 1983. Right: 42 U.S.C. § 1983.

Writing "supra" for cases is the single most common short form error in student legal writing.

Hereinafter: Assigning a Short Name

Sometimes a source's full name is so long that even a shortened form would be unwieldy, or you want to assign a memorable label. Bluebook Rule 4.2(b) allows you to use "hereinafter" at the first citation to assign a short name for future references.

The Hereinafter Format

Include "[hereinafter Short Name]" after the full citation.

5. Restatement (Second) of Torts § 46 (Am. L. Inst. 1965) [hereinafter Restatement]. 18. Restatement, supra note 5, § 48.

Once you have assigned "Restatement" as the short name, you can use it in subsequent supra citations instead of restating "Restatement (Second) of Torts".

When to Use Hereinafter

Use "hereinafter" sparingly. The Bluebook recommends it only when:

• The full title is long and cumbersome
• The standard short form would be ambiguous
• You are going to cite the source many times

For most cases and books, a standard shortened case name or author-based supra is clearer.

Complete Example: A Real Footnote Sequence

Here is a complete footnote sequence showing how all the short forms work together in a realistic passage.

1. Marbury v. Madison, 5 U.S. (1 Cranch) 137, 177 (1803). 2. Id. at 179. 3. Alexander Hamilton, The Federalist No. 78, in The Federalist Papers 464, 466 (Clinton Rossiter ed., 1961) [hereinafter The Federalist No. 78]. 4. Id. at 467. 5. Marbury, 5 U.S. (1 Cranch) at 178. 6. The Federalist No. 78, supra note 3, at 469. 7. Cass R. Sunstein, One Case at a Time 54 (1999). 8. Marbury, 5 U.S. (1 Cranch) at 180. 9. Sunstein, supra note 7, at 58.

Walking through the sequence:

• Footnote 1 is the first full citation to Marbury.
• Footnote 2 uses Id. at a different page (still Marbury).
• Footnote 3 is the first full citation to Hamilton's Federalist No. 78, with "hereinafter" assigning the short name The Federalist No. 78.
• Footnote 4 uses Id. at a different page (still The Federalist No. 78).
• Footnote 5 returns to Marbury after an intervening source, so it uses the shortened case name with "at".
• Footnote 6 returns to The Federalist No. 78 (a non-case source), so it uses supra with the hereinafter short name.
• Footnote 7 is the first full citation to Sunstein's book.
• Footnote 8 returns to Marbury again, using the shortened case name form.
• Footnote 9 returns to Sunstein, using supra.

Notice how cases and non-cases use different short forms. This is the core of Rule 4 and Rule 10.9 working together.

Common Mistakes and How to Avoid Them

Using supra for cases. This is the most common Bluebook short form error. Supra is for books, articles, legislative materials, and treatises. Cases use shortened case names with "at". Never write "Brown, supra note 3, at 495".

Using id. after an intervening citation. "Id." only works when the immediately preceding citation (or the last citation in a multi-citation footnote) is the exact source you are referring to. If anything else has been cited in between, you must use a full short form instead.

Forgetting to italicize Id. and its period. "Id." is italicized, including the period after it. Writing "Id." without italics is a common typo. The "at" and pin cite that follow are NOT italicized.

Using shortened case names without "at". When using the shortened case name form, you must include "at" before the pin cite: "Brown, 347 U.S. at 495". Writing "Brown, 347 U.S., 495" or "Brown at 495" (without the volume and reporter) is incorrect.

Choosing the wrong party for the shortened case name. Use the more distinctive party. For government cases, this often means skipping "United States" or "Commissioner" and using the private party's name instead. Commissioner v. Glenshaw Glass Co. becomes Glenshaw Glass, not Commissioner.

Overusing hereinafter. "Hereinafter" should be reserved for sources with long or unwieldy names. Assigning hereinafter labels to short, memorable titles is unnecessary and clutters the first citation.

Mixing italics for "at". The "at" in short forms is not italicized. Only "Id." (and its period) is italicized. Writing "Id. at 498" is wrong. The correct form is "Id. at 498".

Using supra note 0 or before the full citation. Supra references must point to a footnote that has already appeared in the document. You cannot use "supra note 15" in footnote 10 because footnote 15 has not been written yet. Always point supra back to an earlier footnote.

Quick-Reference Table

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Tools and Resources

• AllCitations Bluebook Generator: Generate a full Bluebook citation for any case or statute to use as your first reference. Short forms you will create manually as your document grows.
• Cornell Legal Information Institute: Free access to cases, statutes, and regulations, useful for verifying the full citations that your short forms will refer back to.
• Georgetown Law Library Bluebook Guide: A free library guide with clear examples of short form citations across source types.

For the foundational rules on citing cases (which you will need before you can use short forms), see our guides to How to Cite a Supreme Court Case in Bluebook Format and How to Cite a Federal Statute in Bluebook Format.

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