Hello everyone, I will try to describe it as simple as I can.
1. The npc will show a option to take one item from the player for some zeny as payment. After this, the NPC will ask how much zeny the player want to sell that item and it will sell item for all the server.
2. Also, it will show a option to player, to take the item back
3. Some money will be required depending on the number of days that the NPC will stay with item. Example: 1 day: 500z; 2 days 1500z...
In other words, it's a NPC that will take your item and sell it for all the server, like a shop. Showing information about who belongs that item, and, of course giving the money of negociation to the player.
Sorry bad english.