Be Back In AWhile
When bbiab ( Be Back in a bit means leaving for 2 - 5 Minutes ) Doesn't fit.
bbiaw means you will be gone for at least 6 - 10 minutes top.
The reason you would use this is because you have to: use the restroom; Answer the door or phone and would not be able to return in a short time.
Chat room and IM (Instant Messenger)usage
Person1:hey did you hear about that thing?
Person1:buzz me when your back.
buzz: To either use YM's Buzz button to get other persons attention or type a letter and press return for same effect.
"Be back in a while"
Although brb means 0 - 15 min, and bbs means 15 - 30 min, and bbl means more than an hour, we lack a term for the 30 to 60 minute range. So, bbiaw is designated for that 30 to 60 minute range, in between bbs and bbl.
In an IM conversation, one would say "bbiaw", and then return between thirty and sixty minutes later.