This error is assuming that `invalid_name` indicates the existence of `/`. That is true the code as it stands today but if the verification function has characters added to then this message will have to be changed with it. Good chance for human error. Perhaps the verification function should return something more like `{error, {invalid_name, "Invalid character..."}}` so that the message is part of the error tuple.

I'm fine with leaving it as is given other things that need to get done and that, from a user perspective, there is no difference.