The rings of the Nazgul generate with names corresponding to 1 through 9 in Elvish (Black Speech would be better but doesn’t have known words for most of the numbers).

There may be an extant patch for this somewhere, but it wasn’t able to be located.

Rings carried by Nazgul are all artifact rings of invisibility. They autocurse and also confer telepathy, see invisible and aggravate monster.