on Just Publishing Advice:
The Oxford comma is either in, or out, depending on your faith in style guides
So, what is this Oxford comma thing, and what is all the fuss about?
In brief, what is also called the serial comma or Harvard comma, is a comma that is inserted before the last items in a list that are preceded by the word and, and sometimes the word or.
The debate about whether to use this comma or not has raged for years but it got a lot of attention due to a court case in the USA.