I have a few questions that I am sure are old hat to mosy of you but, regardless, here I go:

I am really confused as to what the difference between 'Hidden City', 'Nested' and 'Back to Back' ticketing are.

I believe that 'Hidden City' is when one purchases a ticket to a further point and then connects through the intended destination. For example, someone purchases a cheap ticket from YYC-YQT and connects through YYZ. Upon arrival at YYZ, this person leaves the airport and does not take the YYZ-YQT segment. It is really only effective on one-way itineraries (on-ward segments cancelled) and violates AC fare rule, correct?

Would nested ticketing be when a person purchases two seperate tickets and one of those tickets is wholly 'nested' within the other? For example:
Ticket one YYC-SEA on AC
Ticket two SEA-TPE on AC
Ticket two TPE-SEA on AC
Ticket one SEA-YYC on AC
I think this is in the same form as what Empress just flew, except I believe he flew on UA transpacific? Is this legal on AC?

The last one is the 'Back to Back' tickets in which you buy a cheap excursion fare from, say, YYC-YYZ and then another from YYZ-YYC. You use the outbound YYC-YYZ on day one and the outbound YYZ-YYC on day two, thereby circumventing the Saturday night stay requirement and saving money. Of course, you could use inbound portions of both tickets to save more money. As I understand, this is also forbidden on AC, correct?

I would really appreciate it if someone would let me know if I've got these right. Thanks so much.