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Case Law: Topics & Key Numbers

West's Topic & Key Number System

West publishes many reporters and digests, so it helps to have an understanding of the topic and key number system before you begin your research.

  1. West's editors read cases and write paragraphs called headnotes summarizing the points of law within each case.
  2. They organize each of these headnotes under a broad subject-heading category known as a topic, and then assign a more specific key number that serves as a sub-heading.
  3. The headnotes, and the topics and key numbers they are organized under, appear at the beginning of each West decision and form the basis for West Digests.
  4. When you read a case, the headnotes at the beginning help you jump to the part of the case where the discussion of the legal issue summarized in the headnote occurs.
  5. Once you know the appropriate topic and key number for the point of law in which you are interested, you can identify cases on your issue in any of West's digests by looking under that topic and key number.

Key Numbers in Print v. Online

A key number consists of two parts: the topic (e.g., Divorce); and the key number itself (e.g., 309.2(2)).

In print, the topic and key number would appear as Divorce 309.2(2).

Online (i.e., Westlaw), there is much more information.

  • 134 DIVORCE
  • 134V Custody and Support of Children
  • 134k309 Modification of support order, decree or judgment
  • 134k309.2 Grounds and rights of parties
  • 134k309.2(2) Change in circumstances in general

These intermediate levels allow you to more specifically direct your search.  A search on any intermediate level will bring up results for all the more specific levels below it.

When searching for a key number in print, you need the topic and the key number (e.g., Divorce 309.2(2)).  However, online you replace the topic with its numerical equivalent (e.g., 134) and add it to the key number (e.g., 309.2(2)) separating the two with a "k."  So the correct key number on Westlaw would be 134k309.2(2).

The same key number may appear under many topics, so you must use both the topic and key number to locate relevant information.

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