We have had a couple of recent incidences where travelers have attempted to obtain United Airlines' seats indicated as "Available" (i.e., blue square) in Concur's Seat Map, but were unsuccessful. Concur already has a seat map icon for "Available - Paid Preferential" but evidently there is a cost associated to Available seats too?  I was hoping "Available" would mean available at no cost.  If not, what icon does?