Value Table
In some cases, you can see when you define a domain that the system checks all the table fields or structure components referring to this domain 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 a foreign key for the field or component. You can override this proposal.
Domain S_CARR_ID (data type CHAR, length 3) in the flight model describes the three-place code of the airlines. All the airlines are listed together with their codes in table SCARR. It is advisable to check fields referring to domain S_CARR_ID against table SCARR. You enter SCARR as the value table for domain S_CARR_ID. If you want to define a foreign key for a field referring to S_CARR_ID, SCARR is proposed as the check table.
A check is not implemented by simply entering a value table. The check against the value table takes effect only when a foreign key has been defined.