Often called the Greengrocer’s Apostrophe because it was seen on market stalls and greengrocers’ shops: carrot’s, onion’s, mushroom’s.
You can see apostrophes used wrongly in some of the most public places: on vans, shop fronts, and billboards. Not checking your punctuation before having something printed professionally can harm your credibility. Would you want the professional service in the image to print your signs? Have you spotted what’s wrong with it?