Items that are bound cannot be lost in PK. Powerful items that are given free by NPCs are often Bound, to nerf them a little. Bound items are not stuck to a character slot, but are tied to the character, and cannot be sold; thus, valuable storage space is taken up by them until they are Destroyed.
Destroying Bound Items Edit
The PW Promotions Agent (between the Lucidsilver Agent and Lucidgold Envoy at their various locations) will give the player a token named, eg, Destroying [X] in exchange for a bound item named X. The token will last three days (72 hours) with a countdown timer on it until it elapses, whereupon the token disappears. Choosing Cancel Item Destruction at the same NPC will return the item and remove the token