I was looking at the link in this reddit post about the explanations of famous logos. The Alfa Romeo logo (about halfway down that image) includes a Biscione and says it is an emblem of the Visconti family. That sparked my interest so I took a quick look at the House of Visconti Wikipedia page which includes the motto "Vipereos mores non violabo", translated as "I will not violate the Snake's uses". I can't find any other information on that motto that seems remotely reliable and can't for the life of me figure out what it means. Can anyone explain this?
Hm. So, I'm not an expert on arms/mottos/heraldry, but I would say part of this is simply a question of translation. Wikipedia's translation isn't incorrect per se, but it would probably sound better in (at least my dialect of) English as "I will not violate the customs/morals of the snake." The snake is, as you say, the biscione from the Visconti coat of arms, and the motto is probably a reference to those arms -- assuming that this is in fact the Visconti motto, I would read it more as "I will be true to my family." But I'd welcome any insight from Italianists!