I wondered if you could sneak in some unicode digit but it seems to reject those too: $ go run z.go # command-line-arguments ./z.go:6:2: identifier

I wondered if you could sneak in some unicode digit but it seems to reject those too: $ go run z.go # command-line-arguments ./z.go:6:2: identifier cannot begin with digit U+0661 '١' ./z.go:7:27: identifier cannot begin with digit U+0661 '١' (I tried a few of them but not all.)