In some cases you can see when you define a domain that all the table fields or structure components referring to this domain should be checked against a certain table. This information can be stored in the domain by entering a value table.
The system proposes the value table as check table when you try to define aforeign key for the field or component. This proposal can be overridden.
Domain S_CARR_ID (data type CHAR, length 3) in the
A check is not implemented by simply entering a value table! The check against the value table only takes effect when a foreign key has been defined.