Originally Posted by
dsquared37
What about a situation where a QR PNH-SGN flight is followed by QR SGN-DOH on separate tix.
How would this be handled? Would a BP be issued for the onward flight in PNH? Would I need to deplane, go to the transit desk and then reboard? At least I'd be assured of not misconnecting.

I don't know if the 2nd BP will be issued in PNH. Could be but could be not. If not, you will have to collect it at a transfer desk (if any).
Another issue to consider when connecting in Vietnam on separate tickets is that many citizenships require a visa to enter Vietnam and if you don't have one (and require one), the airlines should logically deny you boarding the 1st flight (to Vietnam) because in the booking (in their system), you just go to Vietnam. Showing an e-ticket for an onward flight is sometimes not enough. In your case (QR to QR), it might be easier to convince them as they can see everything in their system and they can even create a kind of link between the 2 PNRs