COBOL data (except key data) that is illegal by database standards is stored in the database as null unless you specifically override this default. (Use the ACUCOBOL-GT runtime configuration file variable 4GL_ILLEGAL_DATA to override.)
The following COBOL data usages are considered illegal by the database:
|USAGE DISPLAY numbers||LOW-VALUES , HIGH-VALUES, and SPACES|
|COMP-2 numbers||HIGH-VALUES and SPACES|
All other numeric types fit one of the preceding cases (depending on their internal storage format)
|DATE fields||The value "zero" and any other illegal conditions as defined by the date's USAGE type (see above)|
BINARY numbers are always legal, and all values are legal in BINARY text fields.