Originally Posted by
jor689
What does Y7, H7, O7 mean?
In addition to what was already explained keep in mind that the numbers aren't necessarily cumulative. So Y7, H7, O7, doesn't mean there are at least 21 seats available. It only means that there are at least 7 seats. There might be 21 (or more) but you can't tell that for sure from these numbers.