In a thread MileageAddict started he mentioned he had to put himself and his son on separate PNRs because he used a voucher. I've searched the forum and have seen this question asked before and only found a vague answer: an agent who knows what they're doing can keep them on one PNR. That wasn't accompanied by any instructions, however, and I've since had two agents tell me that's not possible. So can it be done? Or must the PNRs be split? And does it matter what type of vouchers? It sure seems to me that it ought to be possible with the Type-B cash-type vouchers since those are simply a form of payment...