Oh yes I've seen apostrophes used incorrectly to denote a plural, I have a great urge to go round with a red marker pen and change them all. My comment was in response to the suggestion "just like an apostrophe will eventually correctly denote a plural (it already does this unofficially, even in formal documentation) ", the implication being it will become correct, shudder, shudder. One of my all-time favourites was a Mercedes Sprint, very new registration carrying "bridal dress's" round Stockport a few years ago, someone had paid a lot of money for the lettering.