Return your 'borrowed' dishes
I have SO MANY problems with this.
First of all, don't put borrowed in quotes like you're trying to be cute. The fact is that the dishes really probably are borrowed. I borrow dishes sometimes and I return them when I'm done. So calm down with the condescending quotation marks.
Secondly, what's with the ridiculous clip art? This sign is clearly serious, you're not happy with the fact that students are stealing dishes, so don't be afraid to get serious and lose the dopey pictures.
Next, I hate the whole, "You won't get in trouble" thing. Like...right. It's pretty much impossible for us to get in trouble unless we do something really inappropriate. And it's really easy to just bring the borrowed dishes in your backpack or purse, get them out at your table, and take them back with the dishes from your current meal.
Also, that is just so many words for a sign. Edit, people. All you really needed was "Please return any borrowed dishes. Thank you!"
Also, stop centering things.