Originally Posted by
danielonn
The airlines and people going to Canada. I was confused with Transborder.
"Transborder" in this case is a term usually applied to flights from Canada to the US where border preclearance is in effect.
It creates a third category of departing passengers for those airports in Canada, where they've officially departed Canada and entered the US already, so they have to be separated both from domestic passengers and from other international passengers.
It doesn't apply to flights from the US to Canada.