Originally Posted by TerryK
The system will perform an availability check for all married segments when you try to END (save) the PNR. It doesn't matter how the segments where entered. You will not be able to END the PNR if there are no availabilities in some married segments. You will get an error message.
As far as I know, the system automatically checks for married segments everytime when agent enters another segment. At least that's my understanding of Apollo, and the OP is discussing about UA's itinerary here.
Let's say, PVD-JFK-LAX-OAK.
PVD-JFK check
PVD-JFK-LAX check
PVD-JFK-LAX-OAK check
If you try to make a reservation by putting fare break at each point, that will be certainly possible like another FTer mentioned. However, you know what will happen to fare in this case.