We now have online access to The Chicago Manual of Style.
The online version of the style manual has the definitive guide to citations in Chicago style. You'll also enjoy reading the Chicago Style Q&A where the Chicago agony aunts answer stylistic questions and offer moral support for writers.
Q. I’m editing a textbook that references a play. Should it be “Act 3,” “act three,” or “act 3”? A solution to this mystery would be greatly appreciated. I’ve looked at CMOS a hundred times for help with this issue.
A. Wow—a hundred times? If you can suggest how we can make section 8.194 more clear, we’ll try to do better in the next edition: “Words denoting parts of long poems or acts and scenes of plays are usually lowercased, neither italicized nor enclosed in quotation marks . . . act 3, scene 2.”
Q. Should “ibid.” in citations be italicized? Are block quotes always a smaller font size than the rest of the text? If a publisher specifies that only U.S. and not British spelling should be used in a manuscript, should quoted words be changed as well?
A. No. No. No.
More help with Chicago citation style is available on the Library's Study & Research Help webpage.