# F-INV336

Source: https://xmlvalid.com/rules/F-INV336

> The documenttype does not match an OIOUBL Invoice and can not be validated by this schematron.

- Level: error
- Rule sets: OIOUBL 2.1 Invoice rules (Denmark) 1.17.2
- Context: `/`
- Test: `namespace-uri(*) = 'urn:oasis:names:specification:ubl:schema:xsd:Invoice-2'`

> cac:CertificateTypeCode must contain a value.

- Level: error
- Rule sets: OIOUBL 2.1 Invoice rules (Denmark) 1.17.2
- Context: `doc:Invoice/cac:InvoiceLine/cac:Item/cac:Certificate/cbc:CertificateTypeCode`
- Test: `normalize-space(.) != ''`

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