Is there a tool? I am looking at some intra-Canada travel on AC, and I cannot figure out the mapping of fare classes on the AC site to AC fare classes listed on the CO.com AC OP mileage accrual chart. The fare classses the AC site are "Tango" & "Tango Plus", but the chart lists of full range of letters. Maybe certain letters are "Tango", and others are "Tango Plus", but I would like some direct confirmation.