XV-AT-01
The line's order reference InvoiceRecipientsOrderReference/OrderID (…) differs from the invoice's OrderID (…); e-Rechnung.gv.at does not accept an invoice for more than one order.
What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
/*:Invoice/*:Details/*:ItemList/*:ListLineItem
not(*:InvoiceRecipientsOrderReference/*:OrderID) or $order = '' or normalize-space(*:InvoiceRecipientsOrderReference/*:OrderID) = $order
Checked with Austria e-Rechnung.gv.at (ebInterface 6.1), Austria e-Rechnung.gv.at (ebInterface 6.0)