I disagree, or rather I don't care if I'm wrong but there are likely millions on my side. I'm 49 years old, grew up eating grilled cheese (American cheese on Pepperidge Farms white bread), often with sliced onion or tomato, and mustard. I had never even heard of a melt until I was probably 35, and even so, I still call a doctored up grilled cheese sandwich a grilled cheese sandwich. It ceases to be grilled cheese only if meat is added.