From their site:
"Select any Medium or Large Pan, Thin N' Crispy, or Hand Tossed pizza with up to 5 toppings or a specialty for just $10.00.
Stuffed Crust Pan and Traditional is available for $1 more.
Duplicate toppings are not allowed and please limit your topping choices to 5 toppings for cook ability issues."
Offer I know works in Iowa. I'm guessing it's available elsewhere. You may have to log into the Pizza Hut website and pick your location before they let you see what coupons are available.
Dunno what's up with the "cook ability" issues. Can't count above the number of fingers on one hand?