I got this in the mail from the Colorado Department of Revenue. It's titled "Notice of Deficiency".
Along with this came nothing. It's my interpretation that this is one of two things. First, it could be a simple notice telling me that they have been deficient in the last year and have not provided the required value for the money I paid them. I don't think that that's what they intended however. My second guess is that they have found my behavior deficient and they have calculated sending them $50.75 will correct this problem. In fact, they are so confident they have elected to give me a $0.75 discount.
I have no idea why I got this, why I'm deficient, why $50 fixes it and why I got a $.75 discount. Nice.