Two different columns exist for this purpose: delivered and received. Quantity delivered is the quantity that the supplier claims to have delivered versus what was actually received or booked in. There is also a notes field beside each line item.
When a delivery is booked in, both the quantity received and the distribution quantity must be assigned to distribution locations.
If the distribution quantity was not entered during an initial delivery book-in, this value can be entered by adding a new delivery to the associated purchase order.
On the deliveries listing page, you can expand each delivery to see the delivery summary as well as individual notes. The delivery listing page will also show you how many deliveries are associated with that particular PO.
Alternatively, you can also add additional deliveries directly from the PO and you will be taken to the same page as shown in the first image. When clicking on the "View Delivery Summary" action button, you will be directed to the delivery summary and any discrepancies between what was delivered and received will highlight in red.