The functionality is not idea in its current guise, as package numbers are not unique to the originating document. As a result I could put the same package number into 10 different vendors and purchase orders on receipt and the lot/serial card off the item ledger entry will show all the packages under the one "lot card" over multiple years and vendors. Consider re coding to create a package no and its item ledger lot card specific to the originating source document(s). In my example a Purchase order. Also consider the other areas this is used and the source documents. Or write the source document stamps into the lot card functionality you are releasing as a simple compromise to make it clearer to the user(s), without them needing to drill into receipt lines and work backwards.