Comment:

The list supports ordering of items. Is this ordering preserved, such that it would be possible later to assemble the list from its items and re-construct the ordering of the items? If so, how is the ordering preserved? e.g., there's no "sequenceNumber" on the item. Or is the "orderedBy" simply saying what the ordering criterion is of the list as presently constituted, without any attempt to preserve that ordering for future re-constitution?