Citation, Documentation of Sources

Q. If a book is not published yet but is under contract, with the manuscript in the copyediting process, and has a publication date and ISBN assigned by the publisher on their website, how is this referenced? Putting “forthcoming” in place of the year ignores the fact that a publication date has been set, and it also applies to books that are less far along, and “in press” seems premature. Is there some terminology between these two?

A. Knowing how often the pitfalls of publishing can delay a book project, Chicago prefers to recommend forthcoming. It’s safer to be vague than to publish a citation that turns out to be wrong. If the stage of publication is important to the topic under discussion, you can always explain in the text or a note rather than try to indicate it in the citation.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]