Originally Posted by jackal

Unless something massive has changed in the last two weeks, W is the code for Saver space--at least it was when I was booking several Saver tickets over the last month.

AS actually has three levels of coach awards: Saver, Choice, and Full Flex. I'm actually not sure what the code for Choice (mid-level) space is (Full Flex is the same as a full-fare ticket, i.e. Y), but I'm pretty darn sure W is for Saver.