Does Reg CC require that information obtained (DL# and State, DOB, etc) when cashing a noncustomer's check be written on the front of the check or can it be written on the back of the check?

Reg CC deals with the availability of deposited funds. It is more likely a bank policy that this practice be carried out. The VAST majority of the checks I review have the information on the back of the check, near the endorsement.

I agree this is not a Reg CC matter. I have never seen anything that requires one or the other other then Reg CC restricts certain areas for use by the depository bank and the paying bank on the back of the check. If the notation of the identification restricts the identification of the depository institution (You) or any other institutions within the chain either going to the paying bank or when being returned from the paying bank, You may be delayed notification of the return due to your own actions. I always have our tellers keep within the endorsers area any ID information. You may look at your state law regarding any restriction of information put on checks.