Originally Posted by
JAXBA
No, multiple tickets can be issued in a PNR. The rules of one ticket have no effect whatsoever on any other ticket in the booking, so you could have all kinds of rules, but applicable only to the sectors that the separate ticket covers.
Maybe think of a PNR as a shopping basket. All your products are in there, but your bread doesn't go bad at the same time as your milk... Now, if you buy a promo; buy milk, get bread free - you can't get money back for the bread later on. But that doesn't affect your bananas...
The only thing that can affect separate tickets, same PNR, is if married segment logic is applied to sectors that are booked separately. AA is 'good' at this - book two flights separately, AA will marry them, even if no preferential availability was used. This can cause issues with ticketing and changes.
Thank you JAXBA. Good explanation!