At this spring’s ACES conference, Chicago Manual of Style editors announced several exciting (for editors, anyway) updates going into effect this fall.

We’ve all grown accustomed to frequent changes in AP style. But changes in The Chicago Manual of Style — those don’t come around as often. The last big update was in 2017, when the 17th edition of CMOS came out. With CMOS 18 set to be released this September (in print and online), those of us who use Chicago style have a few months to prepare for some adjustments.

Here are the highlights.

Singular “they”

CMOS will now consider the generic singular “they,” “their,” and “them” acceptable in all forms of writing, including formal writing. This applies to situations when a person’s gender is unknown or must be concealed.

Note: CMOS 17 included the first entry guiding authors to use singular “they,” “them,” and “their” when referring to individuals who use these words as personal pronouns.

Conscious language

CMOS will add sections on Indigenous languages and sources, expand its guidance on accessibility, and revise its section on inclusive language.

Note: In 2020, CMOS editors announced they would begin capitalizing “Black” when used as a racial and ethnic identity. This change came between editions, a rare move by CMOS.

Place of publication

When citing books, authors will no longer be required to indicate the city of publication. 

Note: CMOS editors acknowledged that the place of publication isn’t always easy to identify — and that the benefit readers gain from this information is questionable.

Titles of works

There are three changes here. First, what CMOS currently refers to as “headline style” will now be called “title case.”

Second, in titles of works, prepositions of five or more letters will be capitalized. (Under the current rules, all prepositions are lowercase, regardless of length.)

Third, if a periodical title includes an initial “The” (as indicated in its masthead or on its cover), authors will retain “The” in running text. (For example, “The New York Times” but “the American Journal of Sociology”). 

Note: This has always been the rule for books.

Proper nouns

A proper noun used in a nonliteral sense will be capitalized according to the first entry at Merriam-Webster.com. The examples CMOS editors give are “french fry” (no change) and “French dressing” (a switch to a capital “F.”)

Capitalization after a colon

If a colon is followed by a complete sentence, the first letter of the first word will be capitalized. If the colon is followed by a fragment, the first letter of the first word will be lowercase.

Note: Chicago’s colon rule will now match AP’s colon rule.

E-terms

While some e-terms (e-commerce, e-waste) will continue to use hyphens, “ebook” and “esports” will join “email” on the hyphenless side.

Compound modifiers

Under current rules, a compound modifier uses a hyphen before a noun and no hyphen after a noun. Under the new rules, CMOS will add some exceptions. For example, “first-rate” will now be hyphenated no matter where it falls in a sentence, and “guest room” will not, even if it comes before a noun.

En dash

When using the names of two or more people as a compound modifier in terms such as “Epstein–Barr virus,” authors will use an en dash rather than a hyphen.

Note: CMOS currently uses en dashes in ranges and in names of state university campuses.