Originally Posted by
CDKing
WY - Australia Passenger Service Charge
IN - Indian User Development Fee
WO - Indian Passenger Service Fee
YM - Indian Development Fee
LK - Sri Lanka Embarkation Tax
I looked them up by googling the following :
fare construction tax code (insert 2 letter code here)
Most of them had results from productforums.google.com which hosts the ITA Software support forum. Some people posted their full fare breakdowns in their questions to google support staff
Thanks so much for taking the time to get the information and for providing a link to the source!