Bind to Account

Bind to Account (BoA or rarely BtA) is a form of item binding that was introduced in Patch 3.0.2. Items that are BoA include heirlooms, Collector's Edition companions, rare archaeology artifacts, the Baby Blizzard Bear, and the Onyxian Whelpling. Account Bound items can be mailed to any character that shares the same Battle.net account, regardless of faction or realm.

With Cataclysm, equipment obtained through Archaeology is also Bound to Account.