Account items are items supplied or obtained during a quest which cannot be taken outside of a quest. Account items are often also exchanged for points or money at the end of a quest. Supply account items include items like rations and supply traps/bombs, and exchangable account items like special mushrooms and wyvern tears. Some account items can also be combined, using the alchemy skill.
Related ThreadsAccount Items - last post by @ Sep 10, 2007
Account Items - last post by @ Aug 22, 2007
Full Item Guide! (In Progress) - last post by @ Mar 3, 2009
Transferring Funds/Items/Equipment - last post by @ Nov 18, 2007