In English language punctuation , a serial comma or series comma (also called an Oxford comma or a Harvard comma ) is a comma placed immediately before the coordinating conjunction (usually and or or ) in a series of three or more terms. For example, a list of three countries might be punctuated either as "France, Italy, and Spain" (with the serial comma), or as "France, Italy and Spain" (without the serial comma). Opinions among writers and editors differ on whether to use the serial comma. In American English , a majority of style guides mandate use of the serial comma, including APA style , The Chicago Manual of Style , The MLA Style Manual , Strunk and White 's Elements of Style , and the U.S. Government Printing Office Style Manual . In contrast, the Associated Press Stylebook and the stylebook published by The Canadian Press for journalistic writing advise against it. It is used less often in British English , but a few British style guide...