Eww... Y is full fare (most expensive and usually most flexible) Economy class; I've never seen YN
(usually I get Y1, YH, or YL) but typically a "N" suffix on a farebasis means Non-Refundable... which is strange because I've never seen a non-refundable Y fare.
Where is the origin and destination? What date?
CO Is My Airline of Choice || Baggage Claim is an airline's last chance to disappoint a customer || Next flts in profile