DERIVATION_EXPRESSION is a 2000 alphanumeric field which allows the user to add programming code for additional computation of the data within the record.

Derivation expressions provide the ability to translate values or to retrieve information otherwise not accessible in an interface format in IDIF. Data from within the Wiki database may need to be translated to match the requirements from a receiving third party system. Also, data within a source file may need to be translated to match the Wiki specifications.