This setting is important if you have multiple scenarios contributing items to the same slot. By default, a content item cannot be added more than once to a single slot. If multiple scenarios do attempt to add an item that already exists in a slot, the item is not duplicated, but its priority is set to the highest of all priorities specified for that item.
Select Permit Duplicate Content Items to change this behavior and allow items to be added more than once. In this case, each instance of the item maintains its own priority.
This option corresponds to allowDuplicates (property of type boolean) in the slot component .properties file.
Note that this option applies to the number of instances of a given item in the list of items for a slot; it does not affect the Item Retrieval setting, which determines the display cycle for all items in the slot.
