Morrowind:Containers

Containers are world objects that have the ability to store other objects inside of them. In most cases, you can access the inventory of these containers by activating them. Many containers also allow for you to store new items in them, which is helpful in keeping items that are not needed currently but may be needed at a later point in the game.

Along with the more obvious types of containers (chests, barrels, crates, etc.) are NPCs, both alive and dead. This is because their inventory can be accessed by activating their body when dead, or by activating them while sneaking to pickpocket while alive.

Container Capacity
Containers in Morrowind have limited capacity, depending on the weight of the items you put inside. 

Small Chest: 25
Sack: 50
Barrel: 50
Basket: 50
Urn: 100
Crate: 200
Chest: 200

There are some exceptions to this rule, such as the legions of urns of bonemeal present in every tomb, which only have a capacity of 10. Also, perhaps due to developer oversight, there are some containers with more weight in contents than you can put in yourself, so objects you take out do not always fit back inside. Additionally, sometimes the randomly generated loot will take the contents over the standard capacity, with a similar result.

Organic and Respawning Containers
Containers in Morrowind can have a few attributes that affect their usability. Many container objects, such as mushrooms or Ebony veins, are marked as "Organic," which prevents any items from being placed inside of them. Organic containers can have an additional attribute that allows their contents to replenish. Oddly, the way the engine works requires any replenishing container to be marked as Organic, so the supply chests present in guild halls are technically Organic.

There exist no containers which respawn their contents and are not Organic. Virtually any container is a safe storage place in the sense that no items will disappear from them after a few days.

A quirk of how the game saves container data does allow you to manipulate contents. The game will generate the contents of a fresh container every time the player enters a cell. If a container in the cell has not been modified (i.e. no items moved into or out of it), then the game will not save its contents. The container can be re-generated when the cell is no longer loaded, allowing a particular player to keep manipulating a random container until it presents the desired loot.

Container Ownership
When a container is flagged as "owned", all objects removed from it are marked as stolen from the owner. This makes such a container undesirable for usage in the event of a surrender to the guards, and the subsequent loss of your items. As with all stolen items, this fact is not tied to the individual references, but becomes a mark on your permanent record.

Locks and Traps
Much like doors containers can be locked and/or have traps placed on them. 

A locked container simply will not open until the lock is deactivated. This can be achieved by using a lockpick, a spell or scroll containing the effect open, or by using the container's specific key.

A trapped container will apply a harmful effect to the player if it is activated before the removal of the trap. They can be removed only by using a probe or by using the container's specific key. There is no spell to remove traps from containers, but using Telekinesis allows one to safely open trapped chests and doors from a distance.