TPA per this http://help.yahoo.com/help/maps/maps-13.html and this:
TIA - Tirana, Albania - Rinas
Again, I don't think the author was specifically referencing the FAA airport designation of TPA, but rather simply abbreviating Tampa International Airport as TIA.
Maybe some Tampa residents will chime in and provide us with the local terminology for the airport.
DEN = FAA abbreviation for Denver. However, the airport is universally referred to as DIA, "Denver International Airport." DIA shows on maps, busses, street signs, and on the news. But the bag tags there say DEN.