You need at least document the duplications when you see it (especially in big code base). Because the rules of three easily become the rule of 87, if you are n

You need at least document the duplications when you see it (especially in big code base). Because the rules of three easily become the rule of 87, if you are not aware of the 86 other "second version" that have been written by people that were knowing only one of the duplicated versions.