> A calzone should have ricotta cheese not mozzarella.

It typically has both. And ricotta is legally not a cheese in Italy (because it's not made from milk).

I thought Ricotta is what's left over after you make another cheese from milk, most commonly cows milk.

Wikipedia says ricotta is made from milk in Italy from the production of mozzarella

Yeah, pretty much this. But the law in Italy defines cheese as something made directly from milk, whereas ricotta is made mostly from whey (you can add some milk, but it's secondary).

Similarly things like mascarpone and yogurt which are not fermented using rennet can't be called cheese.

Regarding the type of whey used to make ricotta it can come from any cheese. In central Italy sheep ricotta is more prized than cow, but you can easily find buffalo and goat ricotta as well.

Whey leftover from Parmesan production is also commonly used to make ricotta

In the USA any of those can be anything.

Sromboli can be ground sausage and cheese on a french bread roll.

Stromboli is American, from Philadelphia. It was named after a movie about a Sicilian island that was popular in 1950, because they just wanted to give it an Italian sounding name.

Afaik they don't serve those in Italy or even that far away from Philadelphia. So "in the USA that can be anything" is ... I guess accurate, for a regional American dish

They are served in Puerto Rico. I find that amusing because there’s local types not found anywhere else.

The Italians, for revenge, do their own cheesesteak sandwich.

Just because some people abuse the language out of ignorance does not make them right ;-)

In Italy it's even worse, it can even be made of rock, dirt and lava.