Citation, Documentation of Sources

Q. I’m puzzled over the correct treatment of the edition number of a title being used in text. Would “second edition” be set off with commas before and after, or just before? Would it be italicized and capped with the title? They were reading The Mysteries of the Cosmos, Second Edition, in class.

A. Because the edition number is not part of a book’s title, we lowercase it and leave it in roman type. You could also reword to fit it more smoothly into the syntax of the sentence: They were reading the second edition of The Mysteries of the Cosmos in class.

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