According to the elite guide for platinum members
Full Coach Fares -- When traveling on a full Y...fare, you can upgrade any time prior to departure on flights operated by Continental Airlines.
Discount Fares -- When traveling on a fare other than full Y...you can upgrade within three calendar days prior to departure on flights operated by Continental Airlines...
So no H immediate upgrades (on any route, at least officially.). What I don't get is if you really want to buy a Y fare ticket how come COOL lets it happen in some cases and not others?
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