Yea, Credo[1], one of the static analysis tools for Elixir specifies it as: Numbers can contain underscores for readability purposes. These do not affect t

Yea, Credo[1], one of the static analysis tools for Elixir specifies it as: Numbers can contain underscores for readability purposes. These do not affect the value of the number, but can help read large numbers more easily. 141592654 # how large is this number? 141_592_654 # ah, it's in the hundreds of millions! Like all `Readability` issues, this one is not a technical concern. But you can improve the odds of others reading and liking your code by making it easier to follow. Should make it more obvious that it is purely a readability thing, and that is obviously subjective anyway [1] https://github.com/rrrene/credo/blob/master/lib/credo/check/readability/large_numbers.ex https://github.com/rrrene/credo/blob/master/lib/credo/check/...