F-LIB375

Invalid …. Must not be negative, unless it has been converted from PEPPOL BIS3

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.

Test
not(starts-with(., '-')) or (/*/cac:AdditionalDocumentReference/cbc:DocumentTypeCode[@listAgencyName = 'ERST'] = 'PEPPOLBIS32OIOUBL')

Checked with Denmark OIOUBL 2.1 Invoice