Originally Posted by
NickB
These rules are stricter than the US rules on exemption from US domestic air transportation tax, which only require a reference in the domestic ticket to the international ticket without requiring them to be conjoined. I have succesfully convinced NW to exempt me from US domestic tax on a tickets bought separately but within the appropriate time bounds of an international ticket (it was hard work, though). This would not be possible for APD.
I bought some tickets off UA for a domestic a couple of years back. The agent asked if I was connecting with an international flight, I said yes (even though the connection was about 36hrs) and bingo, fare falls about $20 each!