I had trouble dealing with Avianca's XS, S, M, L and XXL fare names. I have been trying to figure out which fare codes I booked in. I need the fare codes for calculating mileage accrual on TK M&S. I might have found where Avianca hides this info:

'Manage your booking' --> fill in booking code and last name --> 'Booking information' --> any of both 'edit' --> 'Purchase conditions' --> 'Full rule text'

Am I correct in assuming that these XS one-way tickets have fare codes Z and S?