Citation of law or legal citation is the practice of referring to authoritative documents and sources. It is a uniform language that permits one writer to refer to legal authorities with sufficient accuracy and generality that others can follow the references. It is a language of abbreviations and special terms.
The purpose of legal citation is to provide sufficient information to the reader of a brief or memorandum to aid in making a decision about which authorities to check as well as in what order to consult them and to allow efficient and accurate retrieval.
The most common sources of authority cited are court decisions (cases), statutes, regulations, government documents, treaties, and scholarly writing.
Typically, a proper legal citation will inform the reader about a source’s authority, how strongly it supports the writer’s proposition, its age, and other, relevant information.
A reference written in legal citation conveys three things, within limited space:
• makes out the document and document part to which the author is referring
• provide the reader with adequate information to find the document or document part, and
• provide sufficient information about the referenced material and its connection to the writer’s argument to assist readers in deciding whether or not to follow the reference.
When lawyers present legal arguments and judges write opinions, they cite authority. They lace their representations of what the law is and how it applies to a given situation with references to statutes, regulations, and prior appellate decisions they believe to be pertinent and supporting. They also refer to secondary literature such as treatises, restatements, and journal articles. Court rules go so far as to authorize judges to reject arguments that are not supported by cited authority. Lawyers who appeal on the basis of arguments for which they have cited no authority can be sanctioned.
For many years, the authoritative reference work on legal citation was a manual written and published by a small group of law reviews. Known by the color of its cover, The Bluebook was the codification of professional norms that introduced generations of law students to legal citation.
U. S. legal citation follows one of:
• Bluebook standard
• ALWD Citation Manual
• Tanbook (New York State Official Reports Style Manual)
• Greenbook (Texas Style Manual, supplements Bluebook)
• Maroonbook (University of Chicago Law School)
• A number of U.S. states have adopted individual public domain citations standards.