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The Chicago Manual of Style Guide: Welcome

This guide will help you format your paper according to the CMoS 17th (2017) edition.

Chicago Manual of Style

Why Cite?

Citation isn't just about doing the right thing, it's about making your writing stronger and improving the quality of all research performed.

Here's three good reasons why we cite:

  1. Giving credit. The idea is fairly straightforward: great writing of all types is built at least in part on the work of others. We honor and acknowledge the ideas that give birth to our own.
  2. Strengthening our position. A large percentage of writing is persuasive in nature. Citing authoritative sources helps to support our key ideas and arguments. By attributing original works, we place our own ideas in a broader, ever-expanding context.
  3. Showing diligence. Without citation, every word, fact, and idea is attributed to you by default. If some of that information turns out to be wrong, it is on you. Citations show our research and our processes. Without them, any error is an error of negligence. In this way, citation isn't just about providing credit, it's about protecting yourself if mistakes are made in your research.

Source: Bailey, J. (2017, May 16). "Why cite? Three reasons to cite your sources." Plagiarism Today. 

Chicago Manual of Style 17 - What's New?

Chicago style for scholarly documentation is used primarily in the humanities, particularly in the discipline of history. The Manual prescribes two systems of documentation: a "Notes and Bibliography" (NB) system and an "Author-Date" system. The NB system uses footnotes or endnotes and offers the author an opportunity to comment or elaborate on the source or text. The author-date system involves in-text citation using parenthetical references. The Chicago Manual of Style (CMoS) offers useful tips on how to correctly format your paper and how to cite the resources you used in your paper. Some examples are featured in the tabs above.

Three most salient changes in the 17th (2017) edition are:

1. Titles for websites

The formatting for titles of websites can now be treated in various ways. What dictates the treatment is whether the website also has a print counterpart, such as newspaper websites. If the site has one, the title is in italics. If it does not, then it is not stylized.


  • The New York Times
  • Wikipedia
  • Forbes
  • Buzzfeed

2. Use of “ibid.”

In previous versions of CMoS, the abbreviation “ibid” was used in footnotes to show the reader that the previous cited source is being cited immediately after. The 17th edition, however, discourages the use of “ibid” in favor of shortened citations. The footnote can instead start with the author’s last name, and include the page number.

Examples (congruent footnote citations without “ibid.”):

  • William P. Tornow, Tokyo Cyberpunk: Posthumanism in Japanese Visual Culture (New York: Palgrave Macmillan, 2010), 124.
  • Tornow, 11.
  • Tornow, 17.

3. Repeating the Year in Certain Author-Date Citations

Chicago Manual of Style has two main sub-styles: “author-date” and “footnote-bibliography.” In an author-date reference list entry, the year may now be repeated for sources that are also identified by month and day, such as journals or websites. This, however, is optional.


Osborne, Mary. 2021. “Futurist Shock.” Lingua Franca (blog). Chronicle of Higher Education, February 15, 2021.

New York Times. 2020. “In New York, Ad Heats Up Race for Mayor.” July 30, 2020.

Below are a few web resources designed to assist you in formatting and structuring your citations according to CMoS.


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Emily Walshe
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This guide was created by my wonderful colleague, librarian Robert Delaney. It has been modified to reflect changes in the seventeenth (2017) edition.