The system is so new, but AACOMAS requests permission to contact each letter write for verification purposes if they feel obligated to do so. With that being said, I don't think the letterhead is that important with the new system since AACOMAS directly states that it is your responsibility to make sure your letter writers realize they have to reply back to AACOMAS (or individual schools) if contacted for verification purposes of the LORs. Does this make sense?