idem is a Latin term meaning “the same”. It is usually abbreviated to id., which is used mainly in legal quotations to designate the source previously cited (cf. ibid.). It is also used in academic citations to replace the name of a recurring author. Id. is widely used in Canadian law and U.S. legal documents to apply a brief description to a section with the same purpose as the previous one. [1] Here, the first citation refers to United States v. Martinez-Fuerte. The volume number cited is 428 and the page where the case begins is 543, and the page number cited is 545. The “U.S.” between the numerical parts of the citation refers to U.S. reports.
1976 refers to the year in which the case was published. The second citation refers to the first citation and automatically contains the same reporter and volume number; However, the page number given is now 547. Id. refers to the citation that immediately precedes, so if the previous citation contains more than one reference, or if it is not clear which reference ID is referring to, its use is inappropriate. Id. is masculine and neuter; Ead. (feminine), is the abbreviation of eadem, which also means “the same”. In this example, Id in the second citation indicates that the author is the same as the previous citation. That is, the author of the second citation is also Justice Macgillivray`s identification number assigned to a case by the court. As an abbreviation, Id.
always takes a period (or period) in British and American usage (see Use of the period in abbreviations). Its first known use dates back to the 14th century. [2]. Here, Id. refers to the decree mentioned in the previous sentence. [1].