Originally Posted by
LilAbner
Something ain't quite right about this statement as I've never seen
ALL fare classes open up 3-4 hours before departure, if there are some seats available on a particular flight.
But, I could be learning something new?

If there are any economy seats available, all economy fare classes open up (Y and lower). First class do not open up if there are no first class seats available. At least in my experience.