A number of grammarians and language teachers often think that punctuation, capitalization, spelling and grammar rules are absolute. The reality is that grammar hardly is black and white. It evolves over time, and depending on your current location in the world – the United States or the British Commonwealth – different rules generally are considered the norm of what constitutes proper written English. Indeed, even within a country, various editors and teachers will espouse different rules.
One such rule is that of the serial comma (aka the series comma, Oxford comma, or Harvard comma). For example, The MLA Style Manual, The Chicago Manual of Style, Strunk and White’s Elements of Style, and the U.S. Government Printing Office Style Manual all give one rule (use the comma) while the Associated Press Style Manual gives the opposite rule (don’t use it)…and the AP rules generally matches what most British style guides say, though even in Merry Old England not all style guides are in agreement.
The serial comma rule issue centers on whether a comma is needed in a list. Consider the sentence Three popular colors are red, blue, and yellow. Supporters of the Oxford comma would say a comma is needed after the second to last word in the series and before the conjunction, in this case between blue and and. The primary reason given for using a comma there is that it makes identifying the individual items in the series easier for the reader.
Those who dispense with the Oxford comma would simply write Three popular colors are red, blue and yellow. They suggest that the individual items in the list are obvious (after all, and serves the same purpose as the comma), and that more punctuation usually means greater reader confusion.
As you can tell, the comma rule is sort of like getting a hardcore Democrat and a hardcore Republican in the room. They’re simply not going to agree.
Bottom line: Use the comma rule that your publisher prefers. Just always be consistent in its application.
Additional note: The Oxford comma generally refers to single words in a series and not to complex phrases in a series. If the items in the series consist of multiple words, almost everyone is agreement that a comma is needed after each item. For example: The Allies fought Nazi Germany under the Hitler dictatorship, fascist Italy under the control of Mussolini, and Imperial Japan under the rule of Tojo.
My name is Rob Bignell. I’m an affordable, professional editor who runs Inventing Reality Editing Service, which meets the manuscript needs of writers both new and published. I also offer a variety of self-publishing services. During the past decade, I’ve helped more than 300 novelists and nonfiction authors obtain their publishing dreams at reasonable prices. I’m also the author of the 7 Minutes a Day… writing guidebooks, four nonfiction hiking guidebook series, and the literary novel Windmill. Several of my short stories in the literary and science fiction genres also have been published.