Originally Posted by ROKNA

The website fare options and the fare basis codes are independent. EI's fares system has two levels, the classic IATA basis codes (Astral) and a product level (Datalex) so the fare class doesn't tell you much.

Smart Economy books into all fare classes except G and Y, but W/Z/A/T/O/R earn 25 and not 50 credits

Saver Economy earn 15 so while they may show a W/Z/A they are not the same, these should only be available on aerlingus.com (so not GDS available but available if the TA is setup to use the EI web TA service). They normally book into A, but on the same flight the smart fare will also book into A, so there is no way to tell the difference.

Its safe to say if the code is not W/Z/A its a smart fare, flex tends to book into G (or Y if you are unlucky)

After R the fares head roughly in the normal alphabet order until you hit business

P is promotional business
U is upgrade business
X is redemption