At Iberia we have 8 tickets absolutely free of charge that are confirmed for any flight... except for embargos seasons which are Christmast, ten days for Eastern in aprl, and July and august.

The seats are discounted at the inventory for the flight... and it is like a full fare confirmes fare Y, you can make flights changes and it is still in HK status...

You just have to take them at least 48h in advance for your intended flights... the only thing is that you can not overbook a flight, or the system will put you on standby. If you do so, you are the very first on the standby list anyway, which is also good.