Alter Aeon Online Help

Keywords are:  'binding bound equipment'

A 'bound' item is an object that is bound to a particular player.  Only
that player can use the item, and the item can not be sold, auctioned,
exchanged, traded, or used by another player.

Some quest items, and some of the more powerful items, are automatically
bound to you when you obtain them as part of the quest.  In general,
most items are not bound to players.