“The Helvetii, a Celtic tribe who battled Julius Caesar, gave their name to the Swiss territory. The Latin name for the country, Helvetia, still appears on Swiss stamps. The letters CH appearing on Swiss cars and in internet addresses stand for the Latin words Confoederatio Helvetica, meaning Swiss Confederation.”
I knew it was for Switzerland since I see it on their numberplates, but I honestly never questioned what it even stood for. So thanks for that :)