“I was working on the proof of one of my poems all the morning, and took out a comma. In the afternoon I put it back again.”
Writers are probably all familiar with the Oxford, Harvard, or series comma—the final comma in a series used right before the conjunction: A, B, and C.
Writers who prefer the Queen’s English use the comma, whereas Americans see it as redundant. I have a number of business clients with style guides that require the comma to be omitted, but only one client that requires it. The latter client has a largely international clientele.
Clarity is a trademark of any good writing, and I think we suffered a great loss when we Americans ditched the extra comma. (Unlike the loss of the unnecessary “u” in words like rumour and humour.) American grammar guides will tell you that you can use the Oxford comma if it adds clarity to your writing. For a detailed and amusing explanation of when to use the series comma and when it's ok to leave it out, I recommend Grammar Girl's: The Oxford Comma, in Pictures.
But I say why invite potential confusion? Why not simply use the comma all the time? After all, consistency is another trademark of good writing.
Lately, I’ve been using the series comma in my manuscripts, and the copy editing department hasn’t been taking them out. Granted, since I am an American, I have to remember to use them, but that’s one of the things that my proofer and I look for in our many, many, many editing rounds.
I’d be curious if other writers like the series comma or if you prefer to omit them. As a reader, do you even notice?