HansGolden

With that vote of confidence, I'd better add a few qualifiers and additional educational points.

Actually, what I said above isn't strictly accurate, though for the purposes of this thread, it gives an accurate picture. These folks above have something called conjunctive ticket numbers. This is because of a weird limitation of old systems, I think maybe the limitation was the number of segments that could be printed on a paper ticket. Whenever the segments exceed a certain number (I think four), consecutive ticket numbers are issued. That's called a conjunctive ticket number and looks like this:
001-9024760246-47
or basically:
001-9024760246 and
001-9024760247

However, despite conjunctive ticket numbers, they are considered one eticket for purposes of all the rules that I can think of. I think there is a hard limit of four coupons (conjunctive ticket numbers) or 16 segments per eticket. I think this is the reason that many RTW tickets are limited to 16 segments.

There are times when the links between GDSes break down, PNRs (reservations) get out of sync, and all sorts of horrible things begin to happen. But that's the exception rather than the norm and it almost never results in good things.

(For instance, I had a client flying MSP to BOS (via ORD) on UA with a stopover there, then continuing to FRA on LH. When we issued the tickets in Amadeus (the same GDS that LH uses), the link between Amadeus and Galileo (UA's system) was down, so Galileo/UA never got the ticket numbers. (There're supposed to be safeguards in place to transmit the data when the link is back up, but the safeguards failed in this case.) The presence of the ticket numbers is what keeps the seats (in that specific booking inventory and simply the space in general; not talking about seat assignments) from being canceled by UA when the ticket time limit (the date at which we can no longer ticket unticketed space) expires. So UA merrily canceled what it thought was unticketed space and when the customer got to the airport, they found they had a legitimate eticket, but no space to go along with it! This was very confusing to us at first because our system still showed those seats on UA as HK (holding confirmed) however Galileo/UA showed them as HX (canceled). UA didn't have eticket numbers in the record but when the customer gave them the eticket number (that's why it's important to always take your eticket number with you to the airport, despite this age of etickets requiring only your ID) they could pull it up manually and see that there had been a technical glitch, but the flight had checked in 100% full. We found later flights for them to BOS and fortunately they had a stopover in BOS or they would have missed their LH flights (of course, we could have prolly put them on LH flights ex-ORD). But that's an example of GDSes not talking to each other and the subsequent disaster that occurs. Fortunately it's a rare occurrence, but I did want to qualify my above statement.)

But I really should go get some sleep before my 6AM SR to ATL tomorrow.