XV-FI-11

A secure invoice (…) needs InvoiceClassification/ClassificationCode; unless agreed otherwise it may be the same as InvoiceTypeCode (Finvoice 3.0 guidelines, 10.5).

error: the document is invalid

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.

Context
/Finvoice/InvoiceDetails[matches(InvoiceTypeCode, '^SEI0[12]$')]
Test
normalize-space(InvoiceClassification/ClassificationCode) != ''

Checked with Finvoice 3.0