Binding an item to your character denotes that it can no longer be traded to another player nor sold on the auction house. It can still, however, be sold to NPC vendors.
There are two bind types:
- Bind on Equip/Use (BoE) - Item will be bound when used or equipped.
- Bind on Pick Up (BoP) - Item will be bound when looted.
A warning will always appear before binding a piece of equipment or when looting an item that is BoP.
Once bound, the item can not be unbound.