What is an "Oxford Comma"?

From (appropriately enough) AskOxford :

“The ‘Oxford comma’ is an optional comma before the word ‘and’ at the end of a list:

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It is so called because it was traditionally used by printers, readers, and editors at Oxford University Press. Sometimes it can be necessary for clarity when the items in the list are not single words:

These items are available in black and white, red and yellow, and blue and green.

Some people do not realize that the Oxford comma is acceptable, possibly because they were brought up with the supposed rule (which Fowler would call a ‘superstition’) about putting punctuation marks before and.”

As for giving a f*%@, no; by American conventions it’s totally unnecessary.

I love grammar Harp. Thanks for the background on that comma.

@Megan, it’s not grammar, usage or diction, but punctuation help. And perhaps, “I love grammar, Harp.” Without that particular comma, you are declaring yourself to Harp, who is taken, I believe.

I too am taken, but I so love grammar (punctuation, etc.), and many of Harp’s responses.

You’re at 10K @gailcalled.

The classic example of where the Oxford comma is useful is in from the acknowledgements page of a dissertation:

“I’d like to thank my parents, Ayn Rand and God.”

Cwi: There are so many things wrong with that sentence.
And none of it is about grammar. Or punctuation help.

Helluv a dissertation, cw. (So glad you are back.)

I’ve been wondering that ever since I heard that song too!

Actually, Nimis, the ambiguity in the sentence is the result of poor punctuation.

Right now you can read it as a list lacking the Oxford comma: the writer is thanking his or her parents, and also thanking Ayn Rand and God. Alternately, you can read “Ayn Rand and God” as being in apposition to “my parents”—implying an equivalence.

Adding the Oxford comma means you can no longer read the two phrases as being in apposition, and means it is unambiguously parsed as a list.

The only problem I have with that sentence is that it includes Ayn Rand.

There is a great discussion on the Oxford comma (which personally I support) in Eats, Shoots and Leaves. Which is also a super awesome book in general.

@Empress; True and it suggests not to use “super awesome” if you can think of a more specific and less overused adjective, like “hilarious.” :-)