Hello.
After I've posted the new guidelines a week ago I've received lot of questions about the VAT/tax code, especially from people from the US, since they have never heard of it and where they could have found one.
So I've asked my accountant to dig deeper into this matter and it turns out the US equivalent for the Italian Fiscal code it's the Social Security Number (SSN). Or the the National Insurance Number issued in the United Kingdom. ( https://en.wikipedia.org/wiki/Italian_fiscal_code )

Anyway a code that identify you as a fiscal entity, regardless you having a job/activity or not.

However, due to US inner policy that seems to discourage to easily give away the SSN, my accountant told me people from this Country will be able to give just their name and address.

Here you can check the new Comm sheet, where I've highlighted that. The remaining points remain the same as the previous update.