# F-LIB221

Source: https://xmlvalid.com/rules/F-LIB221

> If ID not specified, Address is mandatory

- 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(cbc:ID) or cbc:ID = '') and (count(cac:Address) = 0)`

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