Serial Commas
A much-debated issue in writing is whether to use a serial comma. The serial comma has been known by many names, including the Oxford comma, the Harvard comma, and the series comma. If you’re wondering what exactly I mean by a serial comma, just look at the previous sentence. There are three items in a series (i.e., the Oxford comma, the Harvard comma, and the series comma) in the sentence, and the serial comma is the comma that appears after “the Harvard comma.” According to The Chicago Manual of Style, three or more items in a series (e.g., eggs, butter, and milk) should have a comma after the second to last item in the series.
The serial comma is used to avoid confusion, as in the following sentence: “I like all kinds of ice cream flavors, like strawberry, coconut and chocolate chip and raspberry.” Without a serial comma, it’s unclear whether you are talking about coconut and chocolate chip ice cream or chocolate chip and raspberry ice cream. Adding a serial comma will never cause confusion, but omitting it might. In my opinion, a serial comma is an important tool for clarity in writing.
There are some style guides that do not use the serial comma, most notably the Associated Press style guide. That is the guide used in writing for newspapers, where space is an issue. In book writing, however, the serial comma should almost always be used. I have personally never run into a publishing house that doesn’t use a serial comma, although I’m sure they exist. Also, the authority on writing for books is The Chicago Manual of Style, which calls for a serial comma.
There is one notable exception, though, that often trips writers up. The serial comma should not be used when you use an ampersand (&). Ampersands usually should not be used in the text of a book but are often used in titles, ads, and other supporting materials. If you are called upon to use an ampersand, remember that a serial comma isn’t needed.