Ironically it was argued by the guy opening a Mexican restaurant because the locals were being assholes and probably racist.
I'm reminded of why tomatoes are legally considered a vegetable - agribusiness tried to use their taxonomic classification as a way to get the cheaper tax rate and the judge decided that their common use and reception as a vegetable was the defining factor.
Funnily I am sure there is a thesis somewhere by disgruntled sandwich fans who define 3d vectors which pass through the side showing its not true.
Its funny imagining the horror on their faces when they realize that there are vectors on the original sandwich that don't pass through bread -> filling -> bread.
Im not sure I agree with that. There is no bread involved, and possibly worse for team sandwich, there is only one continuous wrapper. I don’t care what the tax man says that shit ain’t a sandwich. If anything it’s a sort of calzone.
We label foods based upon the number of carb sides.
Open face sandwiches are not a thing. A sandwich requires two non-contiguous opposed bread layers, otherwise it isn't a sandwich. It's a pie. A bottom carb layer with a top layer of substance. Pizza, pie, "open face sandwiches", and French parfait are all pies.
Now, by having only one contiguous bread, but covering three sides, that would put tacos, hotdogs, Philly cheese steaks, and subs all in their own category (arguably a misshapen pie, but that's a deeper debate).