MLA, CMoS, AP, ACS, APA (not to be confused with AP), and countless others are thrown around from grade school through college and into the professional world. Some writers complain about the different style guides, giving little thought as to their purpose.
The guidelines—aka house styles—provide uniformity by topic and intent. Some house styles are universal while others are arranged by intent. A lawyer writing up a citation to present to court wouldn’t use a general guideline like Chicago Manual of Styles (CMoS) but instead would use Oxford Standard for Citation of Legal Authorities (OSCOLA), The Bluebook: A Uniform System of Citation, ALWD Guide to Legal Citation, formerly ALWD Citation Manual, or New York Style Manual depending on where they were located in the world and the intent of said document.
In the same thread, a fiction writer wouldn’t need to focus on a style that leans toward footnotes and source citations. A style guide for a lawyer would be too dry, to disorganized, and boring for a work of fiction.
Newspapers and journalism are for relaying information in a consentent manner. While the CMoS helps, they would use something like The Associated Press Stylebook, The Fourth Estate’s News Style Guide, The New York Times Manual of Style and Usage, The Wall Street Journal Guide to Business Style and Usage, or even The BuzzFeed Style Guide. From Wallstreet business news to global and local events, journalism has a guideline to make sure the information is available and laid out.
But why does that matter?
It all comes down to marketing. The guidelines are there to provide uniformity across the readership and the creative world and adapt to the changes as needed.
The style guides make sure readers of that type know that is what they have picked up—general writing, legal docs, academic, business, computer, editorial, etc.
The information is in the same location throughout the various releases. Look at newspapers where the date is in the same location, the columns are in the same type and size, and many other subtle things. Important things are above the fold. Topics are divided by sections—sports, lifestyle, business.
The medium through which something is distributed can affect layout. Print contents with the type of paper, type of binding, indexes/appendixes/table of contents, how someone is going to use it/hold it/distinguish it from other works in a similar thread. Electronic has flowable text, pixels, viewing sizes, and just as many considerations as print.
For fiction writers, we have submission guidelines and publishing guidelines.
Submission guidelines help editors/agents find information, if pages are missing, the end of the document, paragraphs start and stop. Shunn.net
For publication, it allows the works to be published by companies like Amazon, Kobo, and IngramSpark, and customer to tell a novel from a magazine from a children’s chapter book from a manga.
You can learn how to do both in Word (mybook.to/WriterGuidePink); for publication, I would recommend programs like InDesign.
Another important guideline in the craft is the Chicago Manual of Styles (mybook.to/CMoS). It leads the charge in the English language. It contains every rule (assumed and true) and provides consistency in punctuation, layouts, and describing idioms and homonyms. Flipping through this massive book, many of the guidelines mentioned above can be found in this book—excluding ones like lawyer or scientific research grant proposals.
The CMoS is the guidebook your editor should be using to edit your manuscript if you speak/plan to publish in English. If they don’t know what it is, that is a red flag to not use them.
The next time you or someone asks “how do I do this—fill in with your question,” realize there are guidebooks available that can provide you detailed information on the why and how. Most style guides can be found at your local library or you can buy the current edition or the previous edition from Amazon or a used bookstore—I wouldn’t go more than 1 edition back from the most recent because they come out with new editions when things change.