# F-CRN181

Source: https://xmlvalid.com/rules/F-CRN181

> No more than one AdditionalItemIdentification class may be present

- Level: error
- Rule sets: OIOUBL 2.1 Credit Note rules (Denmark) 1.17.2
- Context: `doc:CreditNote/cac:CreditNoteLine/cac:Item`
- Test: `count(cac:AdditionalItemIdentification) > 1`

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