This has to be worth a try....
It's actually the same for possessives, for example 'Richard's piano' is short for 'Richard, his piano'.
One possible exception is with letter grades. "I earned three A's and two B's." An apostrophe is permissible in most similar cases.
In fact, it should be a's and b's, with the italics.
Where did you read that? This is from a college style page:"grades[:] No quotation marks around letter. No italics, no boldface. For plural of any letter grade, use an apostrophe and an s (three A's, two B's, two I's.)"
An apostrophe is permissible in most similar cases.
word . . . word
What a load of bollock's
Such as?
I'm glad someone started a thread on this, I was thinking of doing so myself.
Misuse of commas (like the comma splice in the example above) deserves its own discussion
How should it look?
My favourite example was on a noticeboard I saw outside a pub in south London last year: