# F-CRN017

Source: https://xmlvalid.com/rules/F-CRN017

> One PaymentAlternativeExchangeRate class must be present when PaymentAlternativeCurrencyCode element is used

- Level: error
- Rule sets: OIOUBL 2.1 Credit Note rules (Denmark) 1.17.2
- Context: `doc:CreditNote/cbc:PaymentAlternativeCurrencyCode`
- Test: `count(/*/cac:PaymentAlternativeExchangeRate) != 0`

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