Tomato sauce, sometimes, but it sure isn’t ketchup!
I see from this list that there are actual food crimes in Italy (I routinely commit at least one of them).
And it’s only a step from deeming something a food crime in a poll, to have actual jailing of foreigners stepping over the line in Italy. Who knows, maybe an overzealous prosecutor will charge someone with a Satanic plot for ordering pasta as a side dish, or drinking cappuccino in the afternoon?
Well, they’d only have themselves to blame!

In my experience, Italians are very passionate about their food and drink, but there are some things that are absolutely forbidden to do, or absolutely mandatory. Non-Italians can ignore these at their own peril!
Well, I’m a full blooded southern Italian, Calabrian to be exact. The pride and joy of Italian cooking is our basic sauce. If that is great, it’s almost impossible to go wrong. If it isn’t, just give up. Outside of Shrimp Scampi, I never even knew about white sauce (alleged) Italian food until I left home and went to college. To a true southern Italian, the white sauce stuff passed off as Italian cooking in some restaurants is GARBAGE. That’s spelled, G-A-R-B-A-G-E. We should class action sue these places for defamation of culinary character!
I remember my first visit to Minneapolis. My hosts were excited because they were going to take me out to a “different” Italian restaurant that was very good. Imagine my dark displeasure when I discovered that EVERY menu item was a white sauce item. They didn’t even have the standard red sauce spaghetti and meatballs! I wanted to burn the place down.

But not a classic ‘vongole’ unless you stop just before the thyme! (Sliced cherry tomatoes and a sprinkle of chilli flakes are acceptable)
Sure, I could sub out the broccoli, black pepper and red bell pepper for sliced cherry tomatoes and chili flakes. But you’re not going to take away my cheese grater until you pry it from my cold, dead hands

But you’re not going to take away my cheese grater until you pry it from my cold, dead hands
I am truly moved!

Actually, it can be argued that it only has egg yolks, parmesan…
yes, I have had long discussions about this with my Roman friends. Carbonara with cream is probably the worst offense after non-breakfast capuccino.
I heard an interesting explanation about the cream though. To make a good carbonara, the egg, pecorino and pasta water have to be added to the just-drained pasta to cook in the heat without curdling the egg. That makes it nice and creamy. It isn’t hard, but there isn’t a big margin for error. In a restaurant it is very difficult to do this in advance to create a large batch to save time, as reheating would curdle the egg. Basically it has to be prepared at that moment for each individual patron. But if you add cream, it can make the sauce creamy despite curdled egg.
Another rule: pasta must never be cut with a knife
And speaking of pasta, unless it is aglio e olio, you should never toss the cooked pasta in olive oil. The pasta should be added directly into the sauce and briefly heated. The oil stops the sauce from properly adhering

Another rule: pasta must never be cut with a knife
Agreed, and also not broken in half before putting in the pot to boil. Pasta is to be “spooled”, which means one uses a large tablespoon along with the fork. You spin the pasta in the spoon so it wraps around the fork properly.
Rule #178 b) ii: You don’t need the spoon for that. Only children and strannieri use the spoon. You should eat pasta with a fork in your right hand and if you have to do something with the left hand, hold a piece of white bread. Use the bread after finishing the pasta to clean the plate.
Better still, use the left hand to gesticulate.

You should eat pasta with a fork in your right hand and if you have to do something with the left hand, hold a piece of white bread.
“White bread”?! It never touches my lips!
Italian bread or even French bread is fine, though.
Italian bread and French baguette are white by any definition I know: made from white, i.e. refined flour. What on Earth is “white bread” in America that you recoil at the mere mention of it?
In the US, it’s called “white clam sauce” to distinguish it from “red clam sauce” which is probably called something else in Italy, if it exists at all.

What on Earth is “white bread” in America that you recoil at the mere mention of it?
Italian Americans often refer to the cheap, low quality supermarket stuff like, for example, “Wonder Bread” as simply, “white bread”. It is meant as a slur for that kind of stuff in general.
By the way, if you want to give it a try, buy a large loaf of Wonder Bread, punch a few whole in the wrapper with a fork so the air can escape, hold it like an accordion, and squeeze it as tight as you can. You can shrink it down to a packet about 6 inches wide. LOL
I was informed of many such rules by the nice ladies who were my neighbors in NY. They also said I wasn’t required to follow those rules because I’m not Italian and thus my mother was not, and neither was my mother-in-law.

Use the bread after finishing the pasta to clean the plate.
I had a waiter collecting my plate, say, in mock surprise, “oh great, the dish doesn’t need to be washed!”
Wonder bread? Never heard of that.
That is white bread (pan de payés or pan rústico) from Spain:
That is white bread (pain de campagne) from France:
Italian white home made white bread (pane rustico):
https://www.agrodolce.it/app/uploads/2014/03/still-life.jpg
I could go on: foccacia, ciabatta, Semmeln, Schrippen, baguette, excellent white breads when well made. Only English white bread made with the Chorleywood method is offensive. I guess that is what Wonder Bread means.

“oh great, the dish doesn’t need to be washed!”
You did right. I hope the waiter transmitted your compliments to the chef.

You spin the pasta in the spoon so it wraps around the fork properly.
I actually bought some special ‘pasta tongs/tweezers’ after watching mesmerised as several Italian chefs artfully twist pasta onto a plate for perfect presentation. Let’s just say it’s a work in progress.

Wonder bread? Never heard of that.
Then you are truly civilized! LOL
Wonder Bread is to bread like a box of those crappy colored chunks of sugar that kids like is to real cereal.

I hope the waiter transmitted your compliments to the chef.
Oh, yes! This was the kind of place where the chef stops out at your table as you are finishing your after dinner drink. I so love long, relaxed, leisurely, meals
Hang in there. If you are successful, we may adopt you into our Italian community.