Originally Posted by CanadaDH

Of course not (although they certainly could on AC flights), but I was assuming that it wasn't outside the boundaries of some simple programming to filter out for sale through the AC site. Something along the lines of, a ticket from "I" space inventory is cancelled through Aeroplan, then the date and flight number are stored to a table, which then prevents any "I" space inventory on that flight from being offered for sale through Aeroplan. It could even be a temporary hold of a few weeks; just enough to make it problematic for a mileage broker being able to turn around a new ticket. I'm just a CIO and not an expert coder by any stretch, but even I could write that logic into my own company systems.