The use of footnotes in text


What does "Op. cit." in a footnote mean

Op. cit. is an abbreviation of the Latin phrase opere citato, meaning "in the work cited". It is used in an endnote or footnote to refer the reader to a previously cited work, standing in for repetition of the full title of the work.[1] Op. cit. thus refers the reader to the bibliography, where the full citation of the work can be found, or to a full citation given in a previous footnote. Op. cit. should never therefore be used on its own, which would be meaningless, but most often with the author's surname, or another brief clue as to which work is referred to. For example, given a work called The World of Salamanders (1999) by Jane Q. Smith, the style would typically be "Smith op. cit.", usually followed by a page number, to refer the reader to a previous full citation of this work (or with further clarification such as "Smith 1999, op. cit." or "Smith, World of Salamanders, op. cit.", if two sources by that author are cited). Given names or initials are not needed unless the work cites two authors with the same surname, as the whole purpose of using op. cit. is economy of text. For works without an individually named author, the title can be used, e.g. "CIA World Fact Book, op. cit." As usual with foreign words and phrases, op. cit. is typically given in italics. The variant Loc. cit., an abbreviation of the Latin phrase loco citato meaning "in the place cited", has been used for the same purpose but also indicating the same page not simply the same work; it is now rarely used or recognized. []

What is difference between "op. cit." and "ibid." ?

In Chicago style, one uses the abbreviation ibid. in footnotes or endnotes when citing the same page from the same consecutively.  If, for example, you reference this article more than once, you may use the abbreviation in your footnotes like so:

  1. Susan Peck MacDonald, “The Erasure of Language,” College Composition and Communication 58, no. 4 (2007): 619.
  2. Ibid.

Op. cit. is used to direct your reader to a previously noted full citation located somewhere else in your work.  It is falling into disuse.  It must include some indication of the work you are referring to, the abbreviation op. cit. and should include the page number.  An example of use would appear like so:

  1. MacDonald op. cit., p.620