Custom field for inventory write off

I have a client who I introduced to Manager who is using manager to monitor the issuing of supplies. We need custom fields for ‘Inventory write-offs’ which will display on printed documents and “show as a column”.
[Edited]

What do you mean custom field which will display in columns? Can you show some screenshot?

Ah, I thought you meant something else. So essentially the same what is already implemented on invoices, quotes, customers etc?

Yes sir, exactly the same

OK, added to the latest version (15.7.2)