Originally Posted by
matthewuk
To make things more complicated (and I don't fully understand this) - I believe there are cases where a flight shows O9 if you are booking in one market (e.g. USA) but is zeroed out if booking in another (e.g. UK).
EF shows availability in the US market, and for July 27 out and August 12 back, expedia.com does show lower fares than expedia.co.uk (though fare rules are not available
). So I would advise booking on expedia.com, or another US site if you are concerned about fare class.