The Serial (or Oxford) Comma

When you place a comma after the word “and” in a list or series, it’s called a serial comma. (It is also called the Oxford comma because the popular Oxford University Press recommends using it.) For example, if you write, “Red, blue, and green are my favorite colors,” that comma after “blue” and before “and” is the serial comma.

The Chicago Manual of Style recommends using the serial comma. The AP Stylebook recommends not using the serial comma, unless leaving it out would cause confusion for the reader about the sentence’s meaning. For example, “I like snickerdoodle, peanut butter and chocolate chip and oatmeal cookies” needs the second comma to clarify whether the last cookies are a combination of peanut butter and chocolate chip or chocolate chip and oatmeal.

Book dedications are another example of when the serial comma is needed to clarify. For example, “To my parents, Todd Smith and Annie Jones” could refer to four different people (mom, dad, Todd, Annie) or it could mean Todd and Annie are the parents.

Refer to your style guide of choice to see whether you need to use the serial comma in your writing or not. And if you think the sentence may still be confusing with the serial comma, rewrite the sentence so your meaning is clear.