Solution : https://service.sap.com/sap/support/notes/1065350 (SAP Service marketplace login required)
Key words :
outbound delivery order assigned, 'free deliveries' tab page, transaction /scwm/tu, selecting free deliveries, terms handling unit, attached correction instructions, free handling units, free deliveries, handling units, correction instructions
Related Notes :
1109846 | Composite SAP note for performance in transaction /SCWM/TU |
1060960 | /SCWM/TU: Search for free deliveries, items and HUs |
1041980 | /SCWM/TU: Error when selecting deliveries / HUs |