I want to book this itinerary: YHZ-YUL-IST-FRA-BKK-SYD (dest) SYD-AUH-CDG(stop)-ZRH-YUL-YHZ
My outbound is just under the MPM but I wonder if I am allowed to go through IST to get to FRA. I can obviously go via Europe but I want to fly TK.

I have been trying to find the nitty-gritty routing rules, but I have had some problems with routing in the past where I made changes to my booking and the new agent said there were certain directions I couldn't go and I can't remember what they were. Any help/advice would be great. Thanks!