Is there the ability for a Proforma Invoice in Sales Order Entry?

We have a customer in South Africa that is requesting an "Invoice" number prior to shiprment. Someone here said it was a Proforma Invoice that is defined as an Invoice stating the Value, Condition, and Transportation Costs typically used for Customs not a demand for payment. Since this Oracle Community is a Global effort I was hoping someone might have an process or know of what we might provide the customer.