Syntax:
DuplicateAllItems TargetContainerID
Example:
DuplicateAllItems BlackBrugoRef
Duplicates all items into the target container. Scripted items are duplicated as new, unscripted (but otherwise identical) versions of themselves.
Note that quest items are duplicated as well, so use with care. Many quests assume that a quest item is unique -- creating a second version of it can have undesirable results.