It's hard to ban ketchup even though putting it on Chicago dogs ought to be a felony for destruction of property. Even the place in your City of Boulder allows it in the restaurant (for hamburgers and fries)and will put it on a dog upon request. I respect the owner of that place, and worked for his partner, but even real Chicagoans have a tough go of enforcing reasonable rules outside the Windy City. And there are people who will put cheese, mayonaise, kraut, or chili on a perfectly good Vienna hotdog. It's a cruel world out there.