In addition, I used to afk out of a bg when I got a phonecall or when I was playing with nabs. Been a while ago, but eventually got too many times booted and got 3h ban. Spoke with a GM and asked him if you could get banned from leaving the BG, and that is not a problem at all. So basically if doorbell rings, if dog/woman starts to bark I just leave the bg and take a 15m deserter rather than risk to afk out.