Field help (SIHORI) 

Determines the origin of the invoice/credit memo/pro-forma invoice.

The origin is comprised of a code of origin and the number of the original document.

For a pro-forma invoice, it can be a quote, an order or a delivery.

For an invoice, it can be a quote, an order or a service contract.

For a credit memo, it can be an invoice or a return.

The number of the original document is only entered if the original document is unique.