"Economy Full" has nothing to do with if there are seats for sale or not, or the booking levels. It just means that every seat either has a body checked in to it, or is pre-assigned. When the CSR releases the reserved seats at 30 min prior to dptr, that "Economy Full" often changes, yet there is no new people booking or checking in, it is just that seats that were allocated to a person are now available. Same thing for F. Just becasue it says "full" doesn't mean that every seat is booked, just that every seat either has been pre-assigned, or has a body checked in to it.