This feature is enabled in the full 200c Professional version but not in Standard/Education. I think for continuity across the products, it would be a benefit to allow this in Standard. the help files currently do not state anything to suggest that you are not able to receive/despatch service/free text items.
Thanks Ian. I've reviewed the help for despatch/receipt of both sales orders/returns and purchase orders/returns. The help will be updated soon to cover which types items are included and not included, when you confirm despatch/receipt in all scenarios.