The real story of the serial (Oxford) comma
What is a serial comma? It is the comma one uses when listing a series of three or more items or events in a single sentence. Here is how serial commas are properly used for American fiction: Donald, Moe, and Trixie walked through the door. The final comma before the ‘and’ is sometimes referred to as the ‘Oxford comma.’
Now you may be confused because there has been much said about not using the Oxford comma. If you are writing a newspaper article or a technical manual, chances are you should not, but if you are writing fiction, you should. If you are a British fiction writer, you also may not. Yes, there are different rules.
For American writers, the serial comma is standard usage in non-journalistic writing. The standard style guide for American fiction is the Chicago Manual of Style, which indicates that the final serial (Oxford) comma should be used. Other common punctuation guides such as the State University of New York (SUNY) and Dictionary.com mirror this guidance. American journalists, however, usually follow the AP Stylebook, which advises against using the final serial comma. I am not sure, but I suspect this is due to save page space or possibly ink.
I use Oxford commas in my fiction writing. I like them. There is a difference between ‘tea, bread and butter’ and ‘tea, bread, and butter.’ (One implies the butter is on the bread while the other implies they are separate.) When I say something like ‘Joe got up, went to the bathroom, and had breakfast,’ it is clear with the comma that he did not eat out of the toilet. When I say ‘Joe, Amy, and Paul got rooms at the inn,’ you know it is three rooms, whereas if I say ‘Joe, Amy and Paul got rooms,’ it leaves you wondering if Amy and Paul are shacking up.
Of course, individual publishers may have their own style guides and may insist that the Oxford comma not be used. This does not make them wrong. They have just made the decision not to follow the standard rules. If, at some time, I decide to pursue publication with a traditional publisher and their style is not to use them, I may comply, but as an independent author, I get to make these calls, and I have decided the last comma adds value and clarity.
I found a good explanation of all of this here, if you would like to see it. http://www.protrainco.com/essays/serial-comma.htm