Billing Document Split
In some countries, you print out billing documents on official forms. They only have space for a limited number of items.
When a billing clerk creates an invoice for a business transaction, the system can automatically restrict the number of line items allowed in the billing document. If the business transaction contains more line items than allowed, the system creates additional billing documents.

You want to print invoices on a form that only has space for five line items. When you bill for 18 billing due list items, the system automatically generates four billing documents, three with five line items, and one with three.
You have set up this function in Customizing for Customer Relationship Management (CRM), by choosing Billing → Country-Specific Functions → Billing Document Split.