Don’t worry, they’re supposed to be confusing.
This isn’t meant to be a tell-all, explain-everything guide to the complexities of AP and CMS Styles, as there are many, many better articles and books out there that do that far better than I can. But it’s a topic that came up recently when a client asked me why I used quotation marks instead of italics for a book title in their article.
Style guides are used to set a standard in a particular form of writing. You’re probably most familiar with MLA (Modern Language Association), as that’s the style used for research papers in high school and college. There are many others, all preferred in one field or another, but the most common are AP (Associated Press) and CMS (Chicago Manual of Style). The former is used in news articles, newspapers, magazines, and other reporting areas. CMS, or Chicago, is for practically everything else, including books and journals. It’s also a bit more flexible than AP, which is mainly concerned about conserving space and using the least amount of characters possible.
On the Web, the styles tend to be more widely varied, especially taking into account informal writing like blog posts. But for the most part, articles and guides tend to be considered news reporting and use AP for its brevity. Some sites have their own style guide, which in my experience, is usually a mix between AP and Chicago, and others use Chicago for its focus on citation and grammatical technicalities.
If you really want to know all the differences between the two styles, you’ll have to buy their respective stylebooks. Both AP and Chicago have the entirety of their guides online, but you’ll need a subscription; you can also find the printed version in bookstores or Amazon. As it’s a hefty, complex tome, Chicago has a free-to-access Q&A section on its site to help people understand the trickier rules.
As a super brief overview, here are a few of the biggest differences between AP and Chicago:
- More general; designed to help writers be accurate and fast when creating content
- More focused on facts than writing style
- For those in the news and public relations
- Information on citing sources relatively simple
- Does not use serial (Oxford) comma
- Uses numerals at 10 and above
- Puts book and other titles in quotes
- State names are abbreviated when used with cities (Sacramento, Cal.)
- Dislikes hyphenation
- Spacing around the em dash
- Usually more abbreviated
- Spacing around, but not between, ellipses ( … )
- More specialized; covers all details of writing in various genres
- More oriented around correct format (punctuation, using numbers, etc.)
- For authors, editors, and publishers of books, journals, etc.
- Extensive information on citing sources
- Uses serial comma
- Spells out numbers up to 99
- Puts book and other titles in italics
- State names are spelled out following city names, unless abbreviated, then uses the two-letter postal code (Sacramento, CA)
- Favors hyphenation for the sake of clarity
- No spacing around the em dash
- Suitable for most writing styles
- Spaced out ellipses, and no spacing around (. . .)
Questions, comments, or just plain confused? Share your thoughts in the comments below!
- Difference Between AP Stylebook and Chicago Manual of Style
- AP vs. Chicago (entire blog on their differences)
- The Chicago Manual of Style Online
- AP Stylebook
- Titles: Quote Marks, Italics, Underlining, or Naked?
- Top 5 Tips to Edit and Write in Chicago or AP Style
- 4 Copy Editors Killed In Ongoing AP Style, Chicago Manual Gang Violence (The Onion)