<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by waitlist:
How can you tell the difference between a economy class Y and a full fare Y.</font>
Unless you are using a paper ticket (which will actually tell you the class you're booked in), the only way to find out is to call AC and ask them what fare class you're booked in. [Full fare is usually booked in Y or M and all the other classes are considered as discounted Economy Class]
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Can you still use a SWU on an economy class Y?</font>
As an Elite, you can use your SWU on full fare Y to Europe and on full fare Y or M to everywhere else.