Q. Could we have some prescriptions for sentence-initial “i.e.,” “e.g.,” “ibid.,” and the like in notes and parentheses? Capitalizing the first letter is widely felt to be awkward (see June Casagrande, “A Word, Please: A Guide to Using Latin Abbreviations, E.g. and I.e.,” December 12, 2015, in the Los Angeles Times), and at least one legal style guide prescribes lowercase “ibid.” at the beginning of a footnote (OSCOLA: Oxford University Standard for the Citation of Legal Authorities, 4th ed., Faculty of Law, 2012). Other style pundits have recommended periphrasis.
A. Chicago would apply an initial cap to each of those abbreviations at the beginning of a sentence, including at the beginning of a numbered footnote or endnote (Chicago styles these like sentences), where “ibid.” would often be the first word (see CMOS 14.34 for examples—and for why we prefer to use a shortened form of the source in favor of “ibid.”):
1. Ibid., 83.
We’d do the same for “i.e.” and “e.g.” (i.e., writing “I.e.” and “E.g.”). But those two abbreviations usually occur in parentheses in Chicago style, and there are no examples of either in the seventeenth edition of CMOS at the start of a sentence or a note. (Attentive readers will have noticed the initial caps for each in the title of the LA Times article in your question, which we decided were being used as nouns when we applied the rules for headline style at CMOS 8.159; “I.E.” and “E.G.” could also work, but we’d reserve that treatment for an all-caps heading. Cf. this Q&A on sp. and spp.)
We do make one exception that’s directly related to your question—for the abbreviation “p.” (page) in a parenthetical page citation at the end of a block quotation (which isn’t Latin but does occur in source citations). Because the “(p. 142)” at the end of the second block quotation in CMOS 13.70 follows a period, one might think that the p should be capitalized: “(P. 142).” But we decided that we prefer consistency for those lowercase p’s relative to other such parenthetical p’s—and that we don’t consider “(p. 142)” to work like a sentence in that context (though the word see may be implied before “p.”).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In dialogue, when a character says “Nam” referring to Vietnam, is an apostrophe necessary? The official name is one word, yet “Viet Nam” is more historical. That would suggest the apostrophe is not needed?
A. The spelling “Viet Nam” reflects how that country’s name is rendered in Vietnamese, which, according to the entry for Vietnam in the CIA’s World Factbook, is “Cong Hoa Xa Hoi Chu Nghia Viet Nam,” which translates to “Socialist Republic of Vietnam.” Vietnamese words are written using the Latin alphabet (usually with diacritical marks, not shown here).
Nam without an apostrophe would be correct then as a shortened form of the Vietnamese spelling of the country’s name. On the other hand, ’Nam would also be correct—as a contraction of “Vietnam.”
So you could choose one form and be consistent—or you could defer to the OED. Although two of its five quoted examples in support of its entry for the word “Nam” (which it labels colloquial) include an initial apostrophe, the headword in the OED is spelled without one.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. When an abbreviation is first mentioned in a footnote, should the abbreviation be spelled out in both the footnote and at the first mention of it in the body of the text, or is spelling it out in the footnote alone sufficient?
A. It can be perfectly acceptable to introduce an abbreviation in a footnote, but if you’re worried about readers who might skip the note, rework your text to define the abbreviation there rather than in the note. You’ll want to do this especially if the meaning of the abbreviation would be difficult to figure out without an explanation—or if you’re using endnotes rather than footnotes.
For an example of how you might use a note to introduce an abbreviation for the title of a frequently cited work (preferably in a footnote rather than in an endnote), see CMOS 14.59.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I am seeing everywhere now that people are putting acronyms in parentheses instead of words, as in “Food and Drug Administration (FDA)” versus “FDA (Food and Drug Administration).” Can you explain to me why this is becoming more common? Parentheses have always been intended for additional information or words of further explanation, which is the opposite of an acronym. It just seems so backwards to me, and if you’re searching for what the acronym stands for, it’s hard to find because the acronym is in the parentheses and used from then on. Please help me understand the logic people are following with this style.
A. It makes sense to put the abbreviation first when the abbreviation is the better-known term—as is arguably the case for the FDA. But there’s no rule against putting the abbreviation in parentheses. In fact, when you introduce an abbreviation primarily as a space-saving device, the convention is to put the abbreviation in parentheses the first time it appears. For example,
According to the Abbreviation Appreciation Society (AAS) . . .
which is shorthand for
According to the Abbreviation Appreciation Society (which we’ll hereinafter refer to as AAS for the sake of convenience) . . .
And though it’s true that you lose a bit of clarity through abbreviation, there are a couple of strategies that can help readers. First, consider reintroducing the spelled-out term alongside the abbreviation in each new chapter or other major division in which it appears. And if your text features many otherwise unfamiliar abbreviations, consider adding a list as described in CMOS 1.44.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. What is the stance of CMOS on single-letter abbreviations for days of the week? In US higher education, the single-letter abbreviations (M, T, W, R, F, S, U) are ubiquitous, though I find no mention of these abbreviations being codified (ISO uses numbers). In prose, I often find myself using these abbreviations in lists of upcoming deadlines.
A. CMOS doesn’t cover those single-letter abbreviations, but we’d consider them to be a convenient shorthand. In the same way, “1/5” can be a handy way of writing January 5.
But because the meaning of “U” and “R” especially may not be clear, and because “1/5” means May 1 for many readers, we don’t recommend either of those forms in formal writing. Where brevity is the main consideration, our preference would be for Su, M, Tu, W, Th, F, and Sa. For those options and two others, see CMOS 10.40. For all-numeral dates, see CMOS 9.35.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. When should you capitalize AM and PM?
A. Capitalize “AM” and “PM” not only in the morning and afternoon but at any time of day or night—unless you’re following Chicago style, in which case use lowercase and periods (10:30 a.m., 5:30 p.m.). See CMOS 10.41.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. How do I abbreviate the word “number”?
A. Avoid num., which is normally reserved for “numeral,” and n., which in Chicago style usually means “note.” For casual prose, the number sign # is common. But even though “number sign” is its Unicode name, that symbol has a number (sorry) of other uses, including as a hashtag and in URLs that point to a specific part of a page.
In most contexts, the best choice is no.—a common form that abbreviates the Latin word numero. That’s what we prefer in source citations for journal articles, as in Critical Inquiry 49, no. 3, which refers to volume 49 (we omit the abbreviation “vol.” in this context), issue number 3, of that journal.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. In CMOS 10.3, I am confused by the meaning of the following sentence, describing “less familiar abbreviations”: “Such an abbreviation should not be offered only once, never to be used again, except as an alternative form that may be better known to some readers.” Would you please clarify? Thank you!
A. Normally, the point of introducing an abbreviation is to save space on subsequent mentions.
The National Endowment for the Arts (NEA) was created in 1965 through an act of Congress. NEA grants have gone to museums, educators, . . .
But it can be helpful in certain cases to give both forms simply as an aid to readers who might know the abbreviation better than the spelled-out form. For example, the International Organization for Standardization is known to many people as ISO, so it would be helpful to include that form even if you were to mention that organization only once. For example,
Times have been presented according to the latest recommendations from the International Organization for Standardization (ISO).
There’s a chance that a copyeditor might query that (“AU: ISO doesn’t appear again. Delete here?”). The author, however, would be right to stet such a suggestion.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I have two questions about the use of AD (anno Domini). First, is it acceptable to leave the abbreviation after the year when it refers to a decade, as in “the 30s AD” (referring to the fourth decade)? Or should that be “the AD 30s”? Second, since AD literally means “in the year of the Lord,” should we avoid saying “in AD 60,” etc., just as we avoid saying “in ibid.”?
A. When a span of years is expressed in the form of a decade, a century, or a millennium, it can safely precede rather than follow “AD.” So write “AD 30” but “the 30s AD” (or “the thirties AD”; see CMOS 9.33), “the second century AD,” “the first millennium AD,” and so forth.
Putting “AD” before the year in “AD 30” and “AD 30–35” and the like (as described in CMOS 9.34) does try to accommodate the Latin phrase behind the abbreviation (one would write “in the year 30,” not “30 in the year”). But Latin antecedents can take you only so far in English. It’s perfectly fine to write “in AD 2020” (despite any apparent redundancy). Likewise, though “ibid.” means “in the same place,” there’s nothing wrong with writing, for example, “referred to in ibid.” (but see CMOS 14.34, which discusses alternatives to “ibid.”).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Is it AKA, aka, or a.k.a.? What about in dialogue?
A. Chicago prefers “a.k.a.” (with periods; see CMOS 10.4). As for dialogue, the answer isn’t “A kay A”—nor is it “also known as.” Writers are sometimes under the impression that because dialogue is supposed to represent speech, abbreviations (and numbers) should always be spelled or sounded out. But if the pronunciation of the abbreviation would be understood by most readers, you can write it as you normally would:
“I’m going to the store, a.k.a. the shop,” my roommate informed me. “Would you like me to get you anything?”
The same goes for an abbreviation like “Ms.” or “NASA” that would be understood (and said) as a word rather than as a series of letters. For some additional thoughts on abbreviations in dialogue, see this post at CMOS Shop Talk.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]