In Indiana you MUST have a title and a registration. If someone sells a vehicle, the new owner has only "x" number of days to re-title it. If he fails to register it for road-worthiness at that time, he does not have to. But, if he decides to later register it for road-worthiness, he'll have to pay the difference from the time it was titled to the present moment. I know... that really bites! If you fail to re-title it within "x" number of days, you are fined a fee. So, often when a person sells to another private individual, they leave the date open and then when the new owner takes it to the BMV for a re-titling in their name, they put the current date in there to avoid the penalty. Is it right? NO. But people do it all the time.
In Indiana, if you don't get a clear title at the time of purchase .... don't do the purchase!