I have searched for this information, but there is nothing precise regarding this operation. However, I would like to recommend checking the built-in documentation, because there are documents providing information related to the functions and available operations. If you can't find anything about this, then I recommend checking the websites listed through Google Search. There are plenty website that offers information about the way Sage X3 works with accounts and invoices.
Browse the results using the following link: https://goo.gl/gJE1MF