When dealing with incomplete returns (items return with parts missing), there is no easy way to add a message to the item as to what is missing.

We would exploit the feature called AllowCheckoutNotes, but it would mean patrons could change the note, and the note is only visible upon check-in.

It would be preferable if there was a to scan the item during check-in and mark it as incomplete, adding a note, and not actually checking it in.  The note would be visible on the patron account next to the item, and would also be visible in the staff view of the item.  This is how I would see this working:

On the Check in (returns.pl) page, there would be a button you would click called "Incomplete return".  A modal would pop up allowing you to scan the barcode and enter a note.  Scanning the barcode would not close the modal.  You would have to submit the incomplete return via button.

The modal would close, returning you to the check in screen, showing the incomplete return, and not checked in.

Marking the item incomplete would give the item a damaged status of Incomplete.  It would not check the item in.  It would send a notification for incomplete returns, along with the note, via e-mail, print or sms or phone.

The note would be visible with the item on the checkout page and on the item record.  The note could also be updated by staff.

The note would be removed from the item once the item is checked in (complete).  I would think the best place to store this message is in the issues table.