Q. Does CMOS prefer a slash or parentheses to denote an alternative? For example, “on/off” vs. “on (off).”

Q. Should there be a space on either side of an ellipsis in the middle of a line when using the Unicode ellipsis rather than three spaced periods? Example: Should there be a … space … like this? I’ve read CMOS 13.50, which says that authors can use the ellipsis character in their manuscripts instead of spaced ellipses, “usually with a space on either side.” But several authors disagree with me as an editor. Most authors insist on no…spaces…like this. Several have them like this… with a space on the right side only, before the clause continues. Thank you for your help!

Q. Can an ellipsis be used instead of a period at the end of a complete sentence?

Q. In formal writing, it is always recommended not to use contractions. But what about the expression “what’s more”?

Q. I was horrified to see that you endorsed using an apostrophe before the s to form plurals! “To aid comprehension, lowercase letters form the plural with an apostrophe and an s (compare ‘two as in llama’ with ‘two a’s in llama’)” (CMOS 7.15). I protest. An apostrophe conveys possession, or a contraction. It should never be used in this context. Please advise where this misbegotten rule came from.

Q. When a question introduces a list, should you use a question mark or a colon? Or both?

Q. I edited a travel book for children, and I would love to know your response to this comment from an Amazon reviewer: “U.S. is spelled US throughout the book; D.C. is also spelled without the accurate punctuation. That sort of inattention to accuracy is inexcusable.” The author has asked me to write a response to this for Amazon. This reviewer seems to think Chicago style is teaching kids bad punctuation habits. Thanks for your help.

Q. What’s the official CMOS stance on double question marks?? I see this a lot in blogs, online magazines, DIY news sites, etc.

Q. Dear CMOS team—a book I am working on as an editor is called (disguised) Sandwich: Imagine the Recipe. Write It Down. Watch It Happen. Are the periods in the subtitle appropriate, or are commas preferred? The periods are driving me crazy, so it would be nice if there were a Chicago rule to say yea or nay.

Q. For catalog copy, how would I write inches symbols with a period at the end of a sentence? (The client wants symbols rather than to spell out inches. That is nondebatable.)

5'' × 4''.
5'' × 4.''

The client says it’s the latter. I say NO WAY. I think the hash marks are not to be confused with an end-quote mark. Please!!! Please!!! Can someone help me out here?