Citation, Documentation of Sources

Q. I’m copyediting a book that’s using endnotes with no bibliography. For multiple authors, should I use the rule in CMOS and list up to ten authors in the first endnote? What if each chapter in the book I’m copyediting is written by a different author, and these authors differ in the number of authors they list in the endnotes? Does the copyeditor then have a role in imposing consistency?

A. In note citations of works with four or more authors, Chicago recommends naming only one author and adding et al. to stand for the rest, but that’s assuming there’s a bibliography. If there isn’t one, it’s up to the writer how many names to include. In a multiauthor work, the copyeditor should decide (or ask) at the start whether chapters need to be consistent only within themselves or across the entire book.

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