Learned a fun one today.

Mrs. YOWgary and I are flying home from Doha in January, on points, and since this is probably one group of people to whom I don't need to explain the attraction of a needlessly-complicated flight routing, we decided to book ourselves a night in Istanbul on the way home.

So, when I search DOH-YOW, it'll offer me DOH-YYZ-YOW, or DOH-CAI-YYZ-YOW, or DOH-YYZ-YQB-YUL-YOW. I mention the last two examples to point out that there's no problem with the routing, or with booking a mix of AC and partner metal.

DOH-IST-ZRH-YYZ is offered by the website, and so is IST-ZRH-YYZ-YOW, but not DOH-IST-ZRH-YYZ-YOW.

So, I called in to see if we could figure out why it's not possible to combine DOH-IST with YYZ-YOW, figuring it'd turn out to be a married-segment thing, or maybe that the YYZ-YOW flights were all dynamically-priced in a way that would have blown up the cost of the ticket.

The agent was experienced enough to know why I was asking, and to know that it was odd that this couldn't happen, but only after she escalated the call did we find out that the problem here is that DOH-YOW does not exist as a city pair within Turkish Airlines' published routings, and therefore could not be booked as a single bound. She could rebook me onto DOH-YOW, but only if we got rid of the Turkish metal.

In this case, I have an 014-ticketed itinerary, for which Turkish Airlines' routing rules still appear to take precedence over Air Canada's.