Q. Can I use the ellipsis character in my manuscript? Or do I need to use Chicago’s spaced periods?

A. Either way is OK as long as you’re consistent. If you use the ellipsis character, put a space before and after it … like that. At the end of a sentence, it follows a period and a space, like this. … If a comma or other punctuation follows, close it up to the ellipsis …, like that. A publisher (or copyeditor) following Chicago style can search for this special character (Unicode 2026) and replace it with Chicago’s spaced periods . . . like that or, at the end of a sentence, like this. . . . Where a comma, semicolon, colon, question mark, or exclamation point follows the ellipsis, it is preceded by a space, like this . . . ; an exception is made for marks that come in pairs, including a quotation mark, “like this . . .”—and a dash . . .—like that (and a parenthesis [or bracket], like this . . .). To keep each ellipsis (and any mark of punctuation that follows) on the same line, nonbreaking spaces will need to be applied for publication (as we’ve done here). An ellipsis can begin a new line, so there is no need to precede an ellipsis by a nonbreaking space.

Q. Do you capitalize both words in “happy birthday”?

A. Not always. To describe the act of wishing someone a happy birthday, neither term is capitalized. To name the traditional song, both words are capitalized: “Happy Birthday to You,” or “Happy Birthday.” In dialogue (as in a published novel or story), the first term would normally be capitalized at the beginning of a sentence: “Happy birthday, Rhoda!” But in a personal greeting, you can style it however you wish: Happy Birthday! 🎈🎈🎈 (birthday-themed emoji optional).

Q. Regarding spelling out round numbers over one hundred—how should we handle numbers like 1,500? It’s more round than a number like 1,543, but it’s also less round than a number like one thousand. And if it should be spelled out, which is preferred, “one thousand five hundred” or “fifteen hundred”? Thanks!

A. According to CMOS 9.4,“The whole numbers one through one hundred followed by hundred, thousand, or hundred thousand are usually spelled out.” The spelled-out form “fifteen hundred” qualifies. But the hybrid form “one thousand five hundred” does not. Paragraph 9.4 is intended to encourage spelling out round numbers like three hundred thousand, not awkward forms like “three hundred thousand six hundred”—or, for that matter, something like “thirty-three hundred thousand,” which would be better expressed as “3.3 million” (see CMOS 9.8). So write “fifteen hundred” or “1,500,” depending on context. (For example, if numerals are otherwise rare in your text, opt for the former.)

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.

A. “DC” (no periods) is the official postal abbreviation, in use since October 1963, when the US Post Office Department (now the US Postal Service) introduced its list of two-letter abbreviations for states and territories (and the District of Columbia). The Chicago Manual of Style now recommends these familiar two-letter forms over the traditional abbreviations. So we recommend not only “DC” rather than “D.C.” but also, for example, “IL” rather than “Ill.” Chicago’s preference for “US,” on the other hand, accords with established usage for other countries (the UK, the former USSR, the PRC) and for most other initialisms and acronyms that take full capitals (NASA, UN, DNA). It is true that many publications still favor the more traditional forms with periods, and those are not wrong. But it would be wrong to suggest that kids can’t learn to appreciate the details that make reading (and editing) so interesting.

Q. I frequently quote material that includes existing footnotes within it. If I don’t want to include the footnote in my own writing, can I insert [footnote omitted] in superscript in place of the footnote number to the original text?

A. The note number can simply be deleted. It adds no meaningful content and risks leading the reader on a wild goose chase for a note in your own text that doesn’t exist. Nor is it helpful to readers to know that you’ve deleted the number; such numbers are a distraction even in the original text, and many books are published without note reference numbers for that very reason (notes are instead listed at the end of the book by page number and key phrase in the text). If, on the other hand, you also want to include the text of the note, use a block quotation, preserve the note number, and present the numbered note below the quotation, preferably in a smaller font size. See CMOS 13.7 for more, including how to handle parenthetical text references.

Q. CMOS 8.154 covers lowercase and CamelCase trade names, but it doesn’t specify how to deal with wordmarks that are partly in italics. I would prefer to set them the same way as any other word, but I would also love an official ruling on this!

A. Italics, like other such typographic treatments in trademarked names (including boldface and color), can usually be ignored. For example, EBSCOhost becomes EBSCOhost; whereas the capital letters are meaningful (“EBSCO” is an acronym based on the founder’s name plus the abbreviation for “Company”), the italics as such are not. You could refer to these as vanity italics, which, like vanity lowercase (e.g., adidas or intel), are intended to support the latest branding efforts by a corporation in service of its product but are less helpful to those of us who write about such things.

Q. What is the proper way to write the commonly used speech abbreviation “twenty-four seven” (meaning 24 hours a day, 7 days a week)? Would one write “24-7” or “24/7” or something else?

A. All of the above. According to Merriam-Webster, the expression is spelled out “twenty-four seven” and can be abbreviated either “24-7” or “24/7” (the latter two are equal variants, which M-W separates by “or”). The entries for the spelled-out and abbreviated forms are separate in M-W, so you’ll have to make a choice. If you are spelling out numbers zero through one hundred (per CMOS 9.2), opt for “twenty-four seven”; if you’re spelling out only single-digit numbers (per CMOS 9.3), choose the first-listed abbreviation in M-W and go with that. There’s no harm, of course, in opting for the second-listed equal variant if that’s what you prefer, but whatever you do, be consistent—twenty-four hours a day, seven days a week.