Originally Posted by mritty

A1-A15 is reserved for Business Select. There may be anywhere from 0 to 15 BS passengers.

So you will be behind:
* any through passengers who are already on the plane when it arrives at your gate.
* any pre-boarders (this does not include families with children under 3, they board later)
* any Business Select passengers
* the 4 non-BS passengers ahead of you (A16-A19)

Your gate agent may call 1-15 first, or may call all of 1-30 as one block. Either way, you should talk to your neighbors and figure out where you fit in the line up - you should be in front of A21 and behind A19.