# F-LIB374

Source: https://xmlvalid.com/rules/F-LIB374

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

- Level: error
- Rule sets: OIOUBL 2.1 Invoice rules (Denmark) 1.17.2, OIOUBL 2.1 Credit Note rules (Denmark) 1.17.2, OIOUBL 2.1 Reminder rules (Denmark) 1.17.2
- Test: `(not(starts-with(., '-')) and . != 0) or (/*/cac:AdditionalDocumentReference/cbc:DocumentTypeCode[@listAgencyName = 'ERST'] = 'PEPPOLBIS32OIOUBL')`

Validate a document against these rules: https://xmlvalid.com/validate