This report depends on the system preference 'TransfersMaxDaysWarning'. If items are not transferred by the number of days defined in this preference a warning will be issued via the 'check this transfer' link.
This report shows all the items from other libraries/branches that are in transit to your branch. The status of all these items is marked as "In Transit"
Once the item has physically arrived in your branch, click "Receive Item". This will change the status of the item from "In Transit" to "Waiting". The item will now show on the "Holds Awaiting Pick Up" report.