Originally Posted by
cynicalmoose
Agreed, but the devil is in the details. E.g. if arguendo B, H and K are semi-flex booking classes, will the same day flight change on a K fare allow you to move to a flight with Y4 B2 H0 K0 M0 L0 on the morning you want to make the change?
This is not rocket science. If Y has 1 seat and the plane leaves more than an hour away, then yes of course you can change.