The new 18th edition of The Chicago Manual of Style is here! While the print version is scheduled for release on September 19, the online version is already available to subscribers. A page of “What’s New in the 18th Edition” lists “the more significant changes, clarifications, updates, and additions” from the 17th edition. It’s a long list!

For those who are familiar with CMOS-17, below is a summary of a few of the changes that most affect book authors. CMOS has them organized by chapter, then by “Changed,” “Clarified,” “New or Expanded.” I’ve organized this summary by category, which seems more convenient for authors.

In some cases, I’ve quoted the verbiage as it appears in CMOS online. Where their wording seemed a bit confusing or verbose, I reworded for clarification and succinctness, as I did in my Proofreading Secrets of Best-Selling Authors. (I am currently working on a second edition of my Proofreading Secrets book, which will be updated according to CMOS-18. It will come out after the new edition of The Christian Writer’s Manual of Style is released, which I’m told will probably happen within the next year, and include any relevant changes from that as well.)

If you write books, whether for traditional publication or self-publishing, and you don’t have either a print copy of the eighteenth edition of The Chicago Manual of Style on order or an online CMOS subscription, I strongly encourage you to invest in this vital resource.

If you’re an editor and you’d like a discount on CMOS online (as well as many other benefits), check out the membership options available at The Christian PEN: Proofreaders and Editors Network, a division of my Christian Editors Association.

If you’d like a longer list with more detailed explanations of these changes, including the guideline numbers for the new 18th edition, email me for my expanded version. (If you don’t have my email address, you can use the Contact page of my website.)

PUNCTUATION

Capitalization

After a Colon: When what follows a colon is not a complete sentence, the first word following the colon is still lowercased (unless it’s a proper noun or other term that would normally be capitalized). When a colon introduces one or more complete sentences, the first word that follows the colon should be capitalized. (Previous editions of CMOS recommended capitalization only when a colon introduced more than one complete sentence.)

Ethnic Adjectives: The adjective “Black” is now capitalized when referring to people. “White” may be capitalized based on author/publisher preference.

Headings and Titles: Prepositions of five letters or more are now capitalized in titles and headings (e.g., A Room with a View but Much Ado About Nothing). Subsequent elements in a hyphenated term that begins with a prefix are now capitalized (e.g., “Anti-Intellectual Pursuits”).

Adjectives Derived from Proper Nouns: These are now capitalized if Merriam-Webster capitalizes them as a first-listed entries. Examples: Swiss cheese, French dressing, but french fries.

Commas

With Identifiers: When a name identifies the only one of its kind, commas are normally required. Examples:

• Desi’s wife, Shondra, has a PhD. (Shondra is Desi’s only wife.)
• Shondra’s brother, Dillon, rescued three dogs. (Dillon is Shondra’s only brother.)

but

• Dillon’s dog Spot is a Dalmatian. (Dillon has more than one dog.)

Such commas may be omitted when the number of spouses, siblings, dogs, etc. is either unknown or irrelevant. A comma may also be omitted when the tone is casual or conversational, as in dialogue. (These are new to this edition of CMOS.) Examples:

• Shondra’s husband Desi is allergic to cats. (Readers will assume Shondra has only one husband, so the commas may be dropped in less formal uses.)
• Desi’s brother Cedric has never owned a pet. (Whether Desi has more than one brother is unknown or irrelevant.)

Commas should be omitted when needed to avoid an awkward possessive. Example:

• Desi’s wife Shondra’s cats are allergic to dogs.

not

• Desi’s wife’s, Shondra’s, cats are allergic to dogs.

With Quotations: An independent clause quoted in the form of dialogue or from text and introduced with said, replied, asked, wrote, or the like (including variations of such terms) is introduced with a comma. If such a quotation is introduced by that, whether, if, or a similar conjunction, no comma is needed. Examples:

• Was it Stevenson who said that “the cruelest lies are often told in silence”?
• He wondered whether “to think is to live.”

A comma can usually be omitted if a form of the verb to be intervenes between the dialogue verb and the quotation. Example: What they said was “The apple falls far from the tree.”

Italics

Foreign Words: Words from other languages used as part of the vocabulary of a multilingual author, narrator, or character no longer need to be italicized.

Series Titles: Series titles based on the title of a book in the series can be italicized (e.g., “the Twilight series”), but do not italicize series names that are based on a place or character in the work (e.g., “the Ramona series”).

USAGE

Singular “They”: Traditionally, a singular antecedent requires a singular pronoun. But CMOS now endorses substituting the third-person-plural pronouns they, them, their, and themselves as generic singular forms in speech, informal prose, and even formal contexts, primarily in three circumstances:

• With indefinite pronouns as a substitute for feminine or masculine forms. (Examples: “No one in the group could remember their great-grandfather’s middle name.” “Given the chance, anybody would try to improve their life.”)

• When the antecedent’s gender is unknown or irrelevant or must remain confidential. (Examples: “Will the driver of the pink sedan please move their car.” “The author wants their privacy protected.”)
  
  
• When an individual has made known a strong personal preference for being referred to with they and them or some other nonbinary singular pronoun rather than he and him or she and her.

Following the grammatical pattern of you, singular they calls for a plural verb even when denoting one person. (Example: “They have a certificate in culinary arts.”) If an individual uses they as their personal pronoun rather than the gendered he or she, such pronouns generally take singular verbs.

GRAMMAR

Comma Splices: When two independent clauses are joined by a comma alone—that is, without the help of a coordinating conjunction—the result is a type of run-on sentence known as a comma splice. (Example: “All watches display the time, some of them do so accurately.”)

In formal prose, comma splices are usually considered an error. The remedy is either to add the appropriate conjunction or to change the comma to a more suitable mark of punctuation.

The occasional comma splice can be effective in conversational prose and creative writing. However, authors should consider in each case whether rewording without the comma splice would result in a clear improvement.

Omitting “That”: The word that may often be safely omitted after the verbs say and think. (Examples: “We said the budget needs to be accurate.” “Hank thought the tire was flat.”) However, it should be retained after other verbs, including near-synonyms, to make it clear that what follows is a clause and not a complement. (Examples: “We declared that the budget needs to be accurate.” “Hank believed that the brochure was outdated.”)

When the subordinate clause begins with a pronoun, the conjunction that can often be safely omitted. (Examples: “Jane assured us she could do it.” “Hank believed his tire was flat.”)

When that is a conjunction, omitting it may result in a miscue or ambiguity, however slight, so it should be included to avoid misreading. (Example: “The plaintiff charged the expenses were recorded as $5,000 instead of $500. [The expenses weren’t charged; therefore, insert that before the expenses.])

SPELLING

Hyphenation: The word ebook is no longer hyphenated.

Numbers: CMOS-18 has new guidelines on when numerals are used, including a list of examples by category. Here are some of the new number guidelines:

• A sentence may begin with a term that consists of a combination of numerals and words (e.g., “7-Eleven”). A sentence may also begin with a year expressed as a numeral, though CMOS prefers it be prefaced with “The year.”
  
  
• Numerals may be used for certain categories of numbers (e.g., ages, centuries, and numbered editions) if many of these appear in a book.
  
  
• Numerals are normally preferred with “a.m.” and “p.m.”; however, words may be used, as in fictional dialogue (e.g., “two a.m.”), if done so consistently.

In nontechnical material, physical quantities such as distances, lengths, areas, and so on are usually treated according to the general rules of numbering. However, it is occasionally acceptable to depart from the general rule for certain types of quantities that are commonly (or more conveniently) expressed as numerals. (Such departures must be consistently applied for like quantities across a work.)

FICTION

CMOS-18 contains several new sections related to writing fiction (or memoir/narrative nonfiction)—a highly beneficial addition. Below are some guidelines of note.

Dialogue

Stuttering: Stuttering is indicated by hyphens, whether for an initial sound or an entire word or phrase. Repetition involving the first word in a sentence may be lowercased unless the word is a proper noun; however, an author/publisher may choose otherwise as long as consistency is maintained. Examples:

• “W-when do we start?” I asked. “I c-ca-ca-can’t find my n-notes.”
• “W-w-will you t-t-talk to K-Karima? What-what about Ph-Phoebe?”

Alternatives to Quotation Marks: CMOS-18 acknowledges that presenting dialogue without quotation marks has been done for centuries. They add, “Such an approach removes a layer of artifice between the reader and the narrator, though at the expense of clarity.”

Sometimes dialogue is presented in the manner of drama, with speakers’ names followed by a colon. More commonly, quotation marks are simply omitted. Each speaker gets a new paragraph, and the punctuation relative to speaker tags is the same as for quoted dialogue.

(My two cents: As a long-time and passionate reader of fiction, I agree with CMOS that omitting quotation marks around dialogue results in a lack of clarity, and I would not recommend it to authors unless they are completely confident that their “combination of punctuation, capitalization, and context” makes it obvious without doubt when a character is speaking and when that character is thinking or observing without audible words.)

Numbers: When writing dialogue in a work of fiction, numbers that might otherwise be rendered as numerals can be spelled out to clarify how they are spoken, although some numbers will be more intelligible as numerals.

Exact times other than full, quarter, and half hours should be rendered as numerals, as should days of the month. Also use numerals that correspond to actual numerals, as in street addresses and room numbers or numbers on signs.

For dialogue that includes more than a few large numbers, it may be more practical to use numerals.

Abbreviations: Abbreviations that are commonly seen in abbreviated form or that would be less intelligible if spelled out may remain abbreviated in dialogue. These include social titles used before a name (e.g., Dr.), brand names that include abbreviations (e.g., AT&T), and abbreviations pronounced as abbreviations.

Unspoken Discourse: Thought, imagined dialogue, and other internal/interior discourse may be enclosed in quotation marks if the speaker/dialogue tag makes it clear that the words were not spoken aloud. Alternatively, italics may be applied. This approach is best used for short passages (at most a sentence or two) occurring infrequently in a work.

If a thought begins mid-sentence, it starts with a capital letter even if not designated with quotation marks or italics.

Text Messages: If words from a text message are run into the text, they may be rendered in quotation marks or italics as long as the narrative makes it clear that these are text messages.

If there are several text messages in a work, they may be given a different typographical treatment to distinguish them from ordinary speech or dialogue.

For long text conversations, texters may be identified in parentheses and italics used for the messages. Instead of using ordinary paragraphs, conversations may be presented as a series of block quotations, indented from the left margin. Example:

(me) Are they here yet?

(him) Yes.

(me) Give me a sec. I’ll be right there.

For authenticity, authors may punctuate and style text exchanges creatively (e.g., omitting punctuation and not using conventional capitalization, grammar, or spelling).

Whatever style is chosen, consistency is crucial.

SOURCES

Rights and Permissions

Artificial Intelligence: If an AI creates something in response to human prompts, that material is not copyrightable. The human must contribute something that will support a copyright, and the copyright will be limited to what that human author contributes. Authors must disclose to the publisher (or in a copyright application for self-publishing) if their work is based on preexisting material.

Epigraphs and Song Lyrics: An epigraph typically consists of a very small portion of a copyrighted work, in a manner that does not in any way affect demand for the original work. If the quotation is chosen for resonance with the text, and if the reader’s understanding is enriched or the reader’s imagination stimulated by that resonance, the epigraph could be viewed as a transformative use of the original and thus be considered fair use. If it is largely decorative, however, the fair use argument is considerably weaker.

The same can be said of limited quotation of song lyrics, poetry, and the like in the context of, for example, fictional narrative or interior monologue.

The publication of a collection of epigraphs or lyrics absolutely requires permission from the authors or other copyright holders.

Obtaining Permissions: Authors wishing to quote from other sources should be familiar with copyright laws and the legal application of fair use. When permission is required, authors need to research the permissions guidelines of the publisher of the material they wish to use in their books. Permissions requests are handled on a case-by-case basis, evaluating each request on its own merits and often involve a fee to be paid by the author.

Copyrights for song lyrics are typically owned by a music publisher, which may be a very large corporation or a small, closely held company. The identity of the music publisher can be determined through the Copyright Office’s online database or through ASCAP, BMI, or another performing rights society. Obtaining permission to quote song lyrics is a very slow process.

Citing Sources

Source Citations: CMOS no longer requires a place of publication for books published in or after 1900. For books published before 1900, the publisher’s name may be omitted, but do include the city/state of publication and date of publication.

CMOS now prefers repeating the name of the author(s) rather than using a 3-em dash to stand in for repeated names in bibliographies or reference lists.

Shortened citations (used instead of “ibid.”) may take one of three forms: author-title (Chicago’s regular short form), author-only, or title-only.

Required elements of a citation that have been mentioned in the text can often be omitted from a footnote because of its proximity to the text (but not from an endnote).

Citing AI-Generated Content: Authors who have relied on content generated by an AI tool must make it clear (in the text or a preface) how the tool was used and whether the AI-generated text has been edited or adapted in any way. Any specific content, whether quoted or paraphrased, should be cited where it occurs, either in the text or in a note. Include the date the content was generated in addition to a version number.

Shortened URLs: In their manuscripts, authors should record full URLs rather than creating shortened versions via a third-party service. Publishers may choose to use short URLs in the published version of a work. Short URLs must be redirected if a source moves to a new location.

For Self-Published Books: Books published independently by the author should be cited according to information on the title page or copyright page. If the book has been published under a publisher or imprint name, it should be cited like other books. If not, “published by the author” can stand in for the publisher’s name. The name of any self-publishing platform or distributor (such as Amazon) is omitted.

For books published by the author before 1900, as with traditionally published books, list the place of publication in lieu of other publication details. Wording such as “printed by the author” may be added to the end of the reference if desired.

PUBLICATION PREPARATION

Copyright notices on manuscripts: Some authors want to put a notice (“Copyright J. Smith”) on their manuscripts before circulating them. But copyright notices are for published works, not unpublished manuscripts. CMOS compares such notices to No Trespassing signs. Some publishers consider these notices unprofessional or even offensive, indicating a lack of trust.

Epigraphs: An epigraph—a quotation that is pertinent but not integral to the text—may appear at the beginning of the book, at chapter openings, or at the beginnings of sections within chapters. The source of the epigraph is usually given on a line following the quotation, sometimes preceded by an em dash (—).

Only the author’s name and the title of the work are needed; further citation is typically not given. However, an unnumbered endnote may be used at the end of the chapter or section before the first numbered note, under the heading “Epigraph.”

Section Breaks: Where a section break is desired, an interior formatter may insert one or more asterisks, a rule, or a type ornament of some kind (e.g., ❦)—or simply a blank line—between paragraphs. (Authors should indicate such breaks with asterisks in the manuscript.)

Acknowledgments: CMOS now recommends placing acknowledgments in the back matter (preceding other back matter) rather than in the front matter for most types of books.