Q. Hi, How would Chicago style the name of the AI hardware company that goes by “io,” founded by Jony Ive and recently acquired by OpenAI? Is it a proper name that should be styled “Io,” following the example of Adidas in CMOS 8.70? Or is it an initialism (abbreviating “input-output,” I guess?), and in that case would it be “IO,” like AT&T? Thanks.
A. That’s precisely the problem: Is “io” a word like “Adidas” (rendered as “adidas” by that company in both logotype and text) or an initialism like “AT&T” (“at&t” in a previous incarnation of that company’s logo)?
An article in Wired announcing the merger gave the name an initial cap, which would suggest that it’s a word: “In the fourth quarter of last year, Io and OpenAI entered into an official agreement for OpenAI to receive a 23 percent stake in Io” (see Lauren Goode, “OpenAI’s Big Bet That Jony Ive Can Make AI Hardware Work,” May 21, 2025).*
Meanwhile, a New York Times article from that same day applied all caps, suggesting an initialism: “On Wednesday, Sam Altman, OpenAI’s chief executive, said the company was paying $6.5 billion to buy IO” (see Mike Isaac and Cade Metz, “OpenAI Unites with Jony Ive in $6.5 Billion Deal to Create A.I. Devices”).
We’ve watched the OpenAI video “Sam & Jony introduce io” (which is also from May 21; we’ve preserved the sentence case in the source’s title and lowercase “io”), but we’re still not sure what “io” is supposed to be—though it’s almost certainly just a name inspired by an abbreviation.
We’re leaning, then, toward “IO” (all caps) as the most reader-friendly choice. “Io” could be one of Jupiter’s moons (among other possibilities). And though you could just go with “io” (if you can’t beat ’em . . .), you’d need to decide whether to retain that form at the start of a sentence or heading (or risk the appearance of inconsistency by applying caps). If you’re worried about being called out as wrong by those in the know, consider adding a clarification at first mention: The merger with IO (styled “io” by the company itself) . . .
__________
* The spelling “Io” (initial cap) could mean it’s an acronym in British style, which would call for “Nasa” instead of “NASA” (an acronym) but BBC (an initialism). But Wired (or WIRED as that publication styles itself) clearly follows US style for acronyms, so “Io” in the article mentioned above suggests that it’s a word (specifically, a proper noun). See also CMOS 10.6.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Small question, but should you use a person’s middle initial in running text or is it acceptable to just use the first and last name? I see mixed usage at my job and would like to encourage consistency with solid grounding from the manual. Thanks!
A. Names are so variable (not to mention personal) that the best we can do is to offer some general guidelines. First, it’s usually fine to use only a first and last name when referring to someone by their full name (as on first mention), even if that person is known to have a middle initial. In fact, for most names it will be preferable to omit a middle initial.
But you’ll want to make an exception for any name that’s normally spelled with an initial or that might be ambiguous without one. This would include people like John D. Rockefeller, Samuel L. Jackson, and Michael J. Fox; it would also include lesser-known individuals whose names usually appear with an initial (whether in published works or elsewhere).
And when naming the author of a particular book or other work, it can be helpful on first mention to use the form as it appears in the work itself (as on a title page), especially if the name may not be familiar to your intended audience. Also (though it probably goes without saying), a name like I. M. Pei generally retains initials whenever mentioned in full (i.e., don’t write “I. Pei”). And don’t substitute an initial for a middle name that’s normally spelled out (e.g., James Earl [not E.] Jones).
In other words, consistency may not be a realistic goal, but with a little editorial discretion backed up by some basic research, you should be able to determine which names will need or benefit from an initial and which ones (usually most of them) can go without.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Does CMOS have guidance for the White House’s recent changes to the names of the Gulf of Mexico and Denali?
A. Relative to matters of style, yes: Spell a generic word like gulf with an initial capital when it’s used as part of a proper name but not otherwise (“the Gulf of Mexico,” but “the gulf”; see CMOS 8.54); don’t add “Mount” before the name Denali (see 8.56); and spell out “Mount” in names like Mount McKinley rather than abbreviating it as “Mt.” (see 10.35).
Other than that, it’s easy enough to confirm that the names of those two geographic entities were officially changed (at least in the United States) to the Gulf of America and Mount McKinley, respectively, in accordance with an executive order issued on January 20, 2025, by the White House. What an author does with that information will then depend on various factors, including a publisher’s house style (if any) and considerations related to historical accuracy.
For additional guidance, see the AP Stylebook, which issues regular updates geared toward those who cover the news. In a pair of updates added on January 30, 2025, that guide says to use the original name for the gulf “while acknowledging the new name,” but, for the mountain, it says that “the Associated Press will use the new official name of Mount McKinley.” For the gulf, AP points to the long history of the older name together with the fact that the gulf shares its borders with Mexico; for the mountain, AP cites the fact that it lies entirely within the United States, which lends broader authority to that name change.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. How would you style Napoleon’s name in something like “They researched the tin buttons on the uniforms of soldiers in Napoleon’s army.” Merriam-Webster has “Napoléon I” under the “Bonaparte” entry but “Napoleon I” under the “napoleon” entry. Encyclopaedia Britannica has “Napoleon I” as its first entry. CMOS 5.128 has “if Napoleon was in fact poisoned” as an example. So should my example sentence have an accent on “Napoleon,” include the “I,” or include “Bonaparte”?
A. Although fidelity to a person’s name is an important consideration, Napoleon Bonaparte entered the English vernacular long ago—without the accent. So, whereas “Napoléon” is the correct spelling of that name in French (where the accent is mandatory), there’s no need to use the French spelling in an English-language context.
As for the Roman numeral, add it only when needed for clarity—for example, to distinguish Napoleon I (or, in French, Napoléon Iᵉʳ) from Napoleons II and III. (Superscripts like the one in “Napoléon Iᵉʳ” are generally retained in an English-language context; see CMOS 11.30.)
As for “Bonaparte,” you can usually add that at your first mention of Napoleon, who is otherwise typically referred to by his first name.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Is it JD Vance or J.D.? I’m having a dispute with an editor who claims to follow Chicago style and she insists on J.D.
A. In Chicago style, initials in a person’s name normally get periods; a nonbreaking space separates consecutive initials. Accordingly, our style would be “J. D. Vance”—as in a bibliography entry for the book Hillbilly Elegy, where the author’s name would be inverted: “Vance, J. D.” We’d add that space even though “J.D. Vance,” with periods but no space, is how the name is credited in that book (as in the 2016 Harper edition). (Unspaced initials with periods is a common style, though published books seem more likely to follow Chicago style, as this n-gram from Google comparing “T. S. Eliot” with “T.S. Eliot” suggests.)
But when initials are used alone, Chicago style says to use no spaces or periods, as in FDR (for Franklin Delano Roosevelt). And we make other exceptions—for example, for pen names (as in H.D., with periods but no spaces, for the poet Hilda Doolittle) or stage names (as in LL Cool J, no periods or spaces). So if Vance himself prefers “JD Vance” (i.e., without periods or spaces), as this Wall Street Journal article from July 17, 2024, suggests, then it’s OK to use that form, at least for mentions in the text. In a bibliography or reference list, on the other hand, you could follow Chicago style, assuming the cited sources themselves include periods (see also CMOS 13.75).
For more details, see CMOS 10.4 and 10.14.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. In CMOS 16.71, why is Leonardo da Vinci indexed under “L”? And in an article that refers to people by surnames on subsequent mention, should he be referred to as “Leonardo” or “da Vinci”?
A. You can ignore Dan Brown and others who’ve rebranded the archetypal Renaissance man as “Da Vinci.” The name is Leonardo, and he came from Vinci (da Vinci), an Italian town in the region of Tuscany.
Leonardo can be referred to in full as Leonardo di ser Piero da Vinci (as noted on page 69 of Walter Isaacson’s 2017 biography, Leonardo da Vinci [Simon & Schuster])—in which “di ser Piero” means he’s the son of a man named Piero (ser is an old social title that was similar to “sir”). Leonardo’s father was also da Vinci, which isn’t a surname but rather an epithet (see CMOS 8.34). Leonardo and Piero are given names (i.e., first names).
Because he lacks a surname, Leonardo da Vinci is properly indexed under “L” and would be referred to in the text as Leonardo—that is, after having been introduced as Leonardo da Vinci.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hello! I know that spellings are always preserved in proper names. For example, in a book written in American English, “Globe Theatre” would not become “Globe Theater.” Does this extend to punctuation? In “St Thomas’s Hospital Medical School” (in London) does it stay “St” or become “St.” when mentioned in a book in American style?
A. British-style punctuation, unlike spelling, can usually be adjusted to conform to the style used in the surrounding text. This includes moving periods and commas inside closing quotation marks (and changing single quotation marks to double), replacing spaced en dashes with unspaced em dashes, and adding periods to abbreviations like “St.”—which, as a form of contraction (the first and last letters of the term are retained), isn’t normally punctuated in British style (see also CMOS 10.4).
Note, however, that the advice relative to periods does not apply to direct quotations from written sources (or, by extension, to titles of works), which should record “St Thomas’s” or “St. Thomas’s” as it appears in the source. See CMOS 13.7 for permissible changes to quotations and 8.165 for permissible changes to titles of works.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hello! I am wondering about the capitalization of trademarks such as “Dad’s root beer” and “Mack trucks,” where the name includes what I consider to be a generic description. My instinct is to make terms such as “root beer” and “trucks” lowercase, but I’m wondering if that’s correct. The companies’ full names in this case are Mack Trucks Inc. and the Dad’s Root Beer Company LLC. Thanks!
A. We agree with your instinct, though it’s never wrong to capitalize the generic term if the company or brand does so in its own materials (as on a company website). With Dad’s Root Beer, the advantages of the extra capital letters are obvious; without sufficient context, “Dad’s root beer” could easily be mistaken for root beer belonging to somebody’s father. Ambiguity is less likely with Mack trucks, and the lowercase t will allow you to compare Mack trucks to, for example, Ford trucks without appearing to be inconsistent.
Another example like Dad’s Root Beer would be Scotch Tape. A capital T could help readers understand that you’re not merely referring to tape from Scotland. 3M’s trademark, however, extends only to the name “Scotch”—as seen in the placement of the registered trademark symbol in “Scotch® Brand Tapes” at the company’s website. Unambiguous examples would include Kleenex tissues and Nike shoes. Whatever you choose, be consistent, and prefer lowercase for a generic term like “root beer” used alone.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hi, when a person has a hyphenated first name, such as Zheng-Jun Gao, how would you style their first initials? Would it be “Z.-J. Gao” or “Z. J. Gao”? Thank you.
A. If you’re following Chicago style, keep the hyphen: “Z.-J. Gao” or, inverted (as in a reference list or index), “Gao, Z.-J.” If you’re writing for the sciences, where initials for given names are more common, and where periods and spaces are often omitted from initials, you could follow the lead of the National Library of Medicine, as detailed in Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers, 2nd ed. According to that guide, hyphens in given names are disregarded when forming initials: “ZJ Gao” or, inverted, “Gao ZJ” (without a comma).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. What is the correct capitalization of “Zoom” and its derivatives when it refers to the essential meeting software that we are all using during the coronavirus pandemic? I’m certain that it is capitalized as a noun—e.g., “I have a Zoom conference at 3:00 p.m.” What about when it’s used as a verb—e.g., “People are zooming/Zooming into online classes all day long.” Thank you!
A. Zoom is a brand name, so you’re right, it gets a capital Z in both noun and attributive forms. (An attributive noun functions like an adjective, as in your “Zoom conference” example.) Capitalization is also appropriate for brand names that have become synonymous with a category, like Band-Aid, Coke, Hula-Hoop, Jet Ski, Xerox, and Zamboni. Those terms are all listed in Merriam-Webster as capitalized trademarks. And though it may seem normal to refer to a hula-hoop or a jet ski in casual prose or creative writing, it’s never wrong to capitalize a brand name.
Verbs are a different story. Some brands immediately enter the lexicon as verbs, and verbs like to be lowercase. Merriam-Webster’s entry for Google, which is limited to the verb form, lists lowercase and capitalized versions as equal variants: “google or Google,” “googled or Googled,” “googling or Googling,” and “googles or Googles.” Ditto Auto-Tune (“auto-tune or Auto-Tune,” etc.). The somewhat older verb “xerox” doesn’t even get a capitalized variant.
But unlike “xerox” or “google” or “auto-tune,” “zoom” has a day job as an ordinary verb. Even if it does enter the dictionary in its trademarked sense, it may be a good idea to retain the capital letter for the sake of clarity. For now at least, prefer “Zooming” over “zooming.”
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]