The Mass Storage system allows players to virtually store stackable items, which can be accessed at any time, from any survival world, via command.
Players will start out with one chest worth of Mass Storage, but can purchase additional storage space at a rate of 500 coins per chest.
As stated in the opening paragraph, the Mass Storage system is intended to store stackable items that would otherwise cause clutter in your chests. As such, most non-stackable items, as well as specialty items (enchanted tools and armor, written books, and potions) cannot be stored using Mass Storage. The only exceptions are saddles, boats, music discs, and horse armor.
If you attempt to store any of the aforementioned items, or exceed your storage space while making a deposit, your items will be rejected and returned to your inventory.