u/Aggravating-Brain867

Apologies if this has been posted before. I received HW that documents are required from Switzerland to prove my dad didn't naturalize in the 80s. I have his little Swiss work visa booklet with all his stamps in and out of the country, it clearly says he is Italian. Does anyone know if they have a CONE equivalent document that I can order? He lived in Lausanne (Vaud Canton).