The MISSING_VALUE field property specifies a value to use if a
    field has not been assigned a meaningful value. See the DIGITAL
    DATATRIEVE or Oracle Rdb documentation for more information on
    how those products interpret the MISSING_VALUE field property.

    The expression you specify must be a valid expression for the
    product evaluating it.

    Products using CDO ignore field elements that contain the
    MISSING_VALUE field property when performing statistical
    operations.