OptionalmatchColumn on the related entity to match against (default 'Name').
OptionalonPolicy when lookup yields no matching record: 'null' (write null), 'fail' (throw error), 'create' (create new record and use its ID). Default 'null'. Note: 'create' creates a new record setting only matchField, intended for lookup/type tables where other columns are nullable or have defaults.
OptionalrelatedTarget related entity name or ID to look up against. Derived from field metadata if omitted.
Foreign-key lookup configuration for resolving a name or match field to a foreign-key ID.