Talk:Air Nomads/@comment-71.190.206.237-20120718231049/@comment-4711309-20120718232812

BSC = Before Sozin's Comet

ASC = After Sozin's Comet

Aang ran away when he was 12, which was the same year Sozin's Comet arrived and the Air Nomads were wiped out, so it makes perfect sense.