I've been noticing that there is a discrepancy between the PQD numbers that appear on the reservation page and confirmation page when you book a ticket on United.com, and the PQD numbers that appear on the e-ticket confirmation email. In the screenshots below, you can clearly see that at the confirmation page the fare is listed as $129, with $22 in taxes and fees. But on my e-ticket confirmation for that reservation, you can see that the fare has changed to $120, with $31 in taxes and fees. The extra $9 comes from the "U.S. Federal Transportation Tax" which isn't displayed on the confirmation page. Has anyone else noticed that? Could be significant if you're buying expensive tickets, since that tax is 7.5% of the base fare. Only applies to domestic tickets.