<P> 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). </P> <P> Opinions among writers and editors differ on whether to use the serial comma, and usage also differs somewhat between regional varieties of English . In American English, not using a serial comma is often characterized as a journalistic style of writing, in contrast to a more academic or formal style . A majority of American 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 advises against it . In Canada, the stylebook published by The Canadian Press advises against it . It is used less often in British English, but a few British style guides require it, notably The Oxford Style Manual . According to The Oxford Companion to the English Language, "Commas are used to separate items in a list or sequence...Usage varies as to the inclusion of a comma before and in the last item...This practice is controversial and is known as the serial comma or Oxford comma, because it is part of the house style of Oxford University Press ." Some use it only where necessary to avoid ambiguity, in contrast to such guides as Garner's Modern American Usage, which advocate its routine use to avoid ambiguity . </P>

What is the last comma in a series called