Possible Duplicate:
“Do’s” and “don’ts” or “do’s” and “don’t’s”?
I always see Do's and don'ts, but in my opinion it must be "Dos and don'ts", or is there any rule where there is an apostrophe in plural? (In German there is never ever an apostrophe in plural, not even in abbreviations, so I guess it's the same in English).
