• 3-minute read
  • 16th July 2018

Ibid. or Op. Cit.? Latin Terms in Academic Referencing

We’ve written about the term “et al.” before. However, there are several other Latin terms you can use when referencing sources in an academic paper. In this post, we look at “ibid.,” “op. cit.” and “loc. cit.,” “passim,” and “cf.”

1. Ibid. (In the Same Place)

One widely used Latin term in academic referencing is “ibid.” This is short for ibidem, which means “in the same place.” It is therefore used for repeat citations:

1. Danielle Ward, Any Questions? (London: DTRT Publishing, 2017), p. 30.
2. Ibid.
3. Ibid., p. 39-41.

Here, for example, we have three footnotes that all cite the same source. We give the full source information in the first footnote. After that, we use “ibid.” in the next two footnotes to show that we’re citing the same source without having to write the publication information out again.

In the second footnote, we use “ibid.” by itself to cite the exact same page as the previous citation. But in the third, we also give page numbers to show that we’re citing a different part of the same text.

2. Loc. Cit. and Op. Cit. (Repeat Citations)

The Latin terms “loc. cit.” and “op. cit.” are also used for repeat citations, but each one has a specific function. “Loc. cit.” is an abbreviation of loco citato, which means “in the place cited.” It is used when citing the exact same part of a source as in a previous citation:

1. Danielle Ward, Any Questions? (London: DTRT Publishing, 2017), p. 30.
2. Loc. cit.

Since it is only used for the same part of a text, you never need to give a page number with “loc. cit.”

Meanwhile, “op. cit.” is short for opere citato, which translates as “in the work cited.” We use this when referring to a different part of the cited text:

1. Michael Legge, Precious Little (New York: Pod Books, 2015), p. 198.
2. Op. cit., p. 102.

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With these terms, if you cite other texts before returning to the one you are citing again, you should also include the author’s surname in the repeat citation to clarify which source you’re referencing. For instance:

1. Michael Legge, Precious Little (New York: Pod Books, 2015), p. 198.
2. Danielle Ward, Any Questions? (London: DTRT Publishing, 2017), p. 30.
3. Legge, op. cit., p. 102.

3. Passim (Scattered Throughout)

“Passim” comes from the Latin word passus, which meant “scattered.” We therefore use it to reference information that is scattered throughout a text:

This usage of “democracy” is repeated throughout the text (Carlin, 2007, passim).

Generally, it is better to give an exact citation. But you can use “passim” to point to relevant information that appears in many different parts of a source.

4. Cf. (Comparisons)

The term “cf.” is short for conferatum. This translates as “compare,” so we use “cf.” when we want to highlight a text for comparison:

The approach adopted by Robins (2002) is a striking contrast to those used by their predecessors (cf. Blackburn, 1974).

In this case, for instance, we’re using “cf.” to suggest a contrast between Robins and Blackburn.

A Final Note

Keep in mind that different referencing systems prefer different Latin terms! If you’re not sure which of these to use in your work, remember to check your college style guide first. And if you’d like any help with the referencing or citations in your work, get in touch with our academic proofreaders.

Comments (4)
4th March 2021 at 16:07
why did loc. cit. and op. cit. evolve or become accepted when meaning/use of is covered with Ibid. or an Ibid., page#? I assume that having an intervening source cited results in situations where op. cit. and/or loc. cit. are used and Ibid. is not? Considering that these types of citations are used only with professional publications, there should be some more realistic examples such as the uses of these with more than one source being cited simultaneously, e.g. Souce 1, Source 2, Source 1, Source 3, Source 1.
    4th March 2021 at 16:39
    Hi, Chris. You are correct that "ibid." is only used for consecutive citations, whereas "op. cit." and "loc. cit." can both accomodate non-consecutive citations. As mentioned in the post, you simply place the author's surname before the abbreviation to do this (e.g., "Legge, op. cit., 106"). I'm not entirely sure what you mean about "professional publications," though. Traditionally, these abbreviations are probably most associated with academic writing, such as research papers and student work. Most style guides now suggest using other approaches, though, such as the shortened footnote format used in Chicago referencing for repeat citations: https://proofed.com/writing-tips/chicago-referencing-repeat-citations/ In terms of the examples, as mentioned above, we did mention non-consecutive citations in the post, including the generic convention of including the author's surname, but I've now added an extra example to illustrate this in case it wasn't clear from the text alone. Keep in mind that these are broad suggestions, though. If you're interested in how repeat citations work for a particular referencing style, make sure to check the relevant style guide.
L. Young
6th July 2021 at 00:03
What about id. (idem)?
    12th July 2021 at 09:13
    Hi, L. Young. What do you want to know? "Idem" and "id." are similar to "Ibid." and used in some legal citation systems. If there's anything more specific than that you'd like to know, please clarify and we can perhaps add something to the post accordingly.

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