`ChamberOfCommerceRegistrationNumber` MUST exist at least once. `ContactPerson` MUST exist at least once. `EmailAddressFull` MUST exist at least once. `FunctionContactPerson` MUST exist at least once. `LegalEntityName` MUST exist at least once. `Municipality` MUST exist at least once. `SoftwarePackageName` MUST exist at least once. `SoftwarePackageVersion` MUST exist at least once. `TelephoneNumber` MUST exist at least once.