Final Fantasy Wiki
A temporary item; note the blue 'Tmp' icon.

Temporary items are a variety of unique items or common items that are given to players in Final Fantasy XI for specific events. Temporary items appear in the item screen, but are not placed in inventory, nor are they counted towards the total number of things a player can carry with him. A player may have up to 40 temporary items at once; this number is not affected by the size of the player's normal inventory.

Temporary items first appeared in Ballista, the player versus player game available to all players with rank 3 or more with the original game. Temporary items can now be obtained in Besieged, Salvage, some Assault missions, Campaign Battles, Abyssea, and Escha. At the end of any of these events, all temporary items will be lost, though this is not a serious drawback. For the most part, they are free, found, or paid for by means other than gil. Temporary items cannot be traded or sold, although unlike normal items they can be destroyed by certain rare monster attacks.