The legal equivalent of a footnote; it appears, however, in the body of a brief or memo. Form is of the essence, so the use of the Bluebook is crucial.

The proper reference (as established by the legal profession) to a case, constitution, statute, legal encyclopedia or legal treatise is called a citation. A citation contains the name of the case or other authority, the name of the book in which it is found, the volume in which it appears, its page or section number and the year decided or enacted. Citations allow any reader to find the source and read it.

E.g. The proper citation for the case allowing women to have an abortion is Roe v. Wade, 410 U.S. 133 (1973). The name of the case includes the name of the plaintiff (Roe) followed by a 'v.' (meaning versus) followed by the defendant's name (Wade). '410' is the volume number where the case is found in the series called United States Reports (abbreviated by 'U.S.') at page 133. The case was decided in 1973.

The production or reference to the text of acts of legislatures, treatises and decided cases in order to support what is advanced.

Works are sometimes surcharged with useless and misplaced citations; when they are judiciously made they assist the reader in his researches. Citations ought not to be made to prove what is not doubted; but when a controverted point is mooted it is highly proper to cite the laws and cases or other authorities in support of the controverted proposition.

The mode of citing statutes varies in the United States, but is generally guided by the 'Bluebook.'

It is usual among the civilians on the continent of Europe, in imitation of those in the darker ages, in their references to the Institutes the Code and the Pandects or Digest to mention the number, not of the book, but of the law, as well as the first word of the title to which it belongs; and as there are more than a thousand of these it is no easy task for one not thoroughly acquainted with those collections to find the place to which reference is made.

The American writers generally follow the natural mode of reference by putting down the name of the collection and then the number of the book, title, law and section. For example, Inst. 4, 15, 2, signifies Institutes, book four, title fifteen, and section two.

Practice. A writ issued out of a court of competent jurisdiction commanding a person therein named to appear and do something therein mentioned, or to show cause why he should not, on a day named. In the ecclesiastical law, the citation is the beginning and foundation of the whole cause; it is said to have six requisites, namely: The insertion of the name of the judge; Of the promovert; Of the impugnant; Of the cause of suit; Of the place, and; Of the time of appearance - to which may be added the affixing the seal of the court and the name of the register or his deputy.

By citation is also understood the act by which a person is summoned, or cited.