You have to comment. IMO, this should be a rule already. There should be an exception in the case of DNWs or spitefic being written but otherwise there's no reason why you can't leave a comment. If you get bland ODAO or coal from a bad writer just say "thanks for writing for me". Commenting should be a basic part of the exchange and yet we let certain people sign up over and over again despite the fact that they can't be bothered to say 'thank you'.

I'd like the optional details rule but I feel like most people with blank signups would just put "." or "anything" and that would become the new blank signup.