# F-LIB235

Source: https://xmlvalid.com/rules/F-LIB235

> At least one field in the Contact class should be specified

- 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 (not(cbc:Name) or cbc:Name = '') and (not(cbc:Telephone) or cbc:Telephone = '') and (not(cbc:Telefax) or cbc:Telefax = '') and (not(cbc:ElectronicMail) or cbc:ElectronicMail = '') and (not(cbc:Note) or cbc:Note = '') and not(cac:OtherCommunication)`

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