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Case Law - What It Is & Where to Find It: Key Numbers

Headnotes/Key Numbers/Digests

Headnotes contain summaries of the key legal issues in a case. Each headnote contains one point of law and is assigned a corresponding Topic & Sub-Topic (Key Number).

West Digests are a multi–volume set of books that organize headnotes (from cases) alphabetically by Topic and Sub-Topic (Key Number). Before the advent of online legal research databases, digests were a very important case finding tool. Digests acted as a subject index to find cases. Researchers could find cases summaries (and citations) by subject matter in the digest and then they could locate the case in a reporter using the citation.

Key numbers can help researchers find cases in other jurisdictions, as well as other primary and secondary sources, because they are uniform throughout the West Publications. West Publications include:

  • West Reporters (see chart on the right)
  • Legal Encyclopedias (American Jurisprudence 2d; Corpus Juris Secundum; New York Jurisprudence 2d)
  • American Law Reports (A.L.R.) (early editions do not have Key Numbers)
  • Statutes published by West (U.S.C.A. & McKinney’s)
  • Westlaw (Online Database)

Which Reporters Use Key Numbers?


Key Numbers (West Products)


No Key Numbers


Supreme Court Reporter (S.Ct.)


United States Reports* (U.S.)


Federal Reporter (F., F.2d, F.3d)


Lawyers Edition (L. Ed., L. Ed. 2d) (Lexis)


Federal Supplement (F. Supp., F. Supp.2d)


New York Reports* (N.Y., N.Y.2d)


New York Supplement (N.Y.S., N.Y.S.2d)


Appellate Division Reports* (A.D., A.D.2d,  A.D.3d)


North Eastern Reporter (N.E., N.E.2d)


Miscellaneous Reports* (Misc., Misc.2d, Misc.3d)

* Indicates Official Reporter