A pizza is only made in pizzeria, is baked directly into the wood stove, over the marble
A focaccia is only made in panificio, is baked into a baking tray
Btw a focaccia barese is a total specific thing (always with oil, olive, and tomato pieces) it was a shock to know this thing does not exist outiside my city
Carbonara is another highly debated dish - here in Roma (where it is was supposedly born ~50 years ago) some people insist you only need egg, where as others insist you need egg and cheese (and then there is the debate over what cheese). I've heard some restaurants stopped serving the dish to prevent heated arguments with their customers.
Even the word for bags in a supermarket can't be agreed on. Here we use "buste", where as in the north they use "sacchetto". Our word there means envelope, so obviously you will get a funny look if you ask for three envelopes when paying for your groceries (the joke is on us though, we use that word for envelope too :P).
Further reading:
http://www.seriouseats.com/2016/02/origins-history-of-roman-...
Ha, that reminds me of sac in the north of France versus poche (the word northerners would use for the thing in their trousers) as used in the south(-west?) to designate a plastic bag in a supermarket...
FWIW, "pizza bianca" is also underspecified, as in many parts of center italy, it might refer to pizza baked from bread makers using the same dough ad the bread rather than pizza dough, just flattened.