Describes a function (returned) value. You can specify a data
    type and a passing mechanism (BY DESCRIPTOR, LENGTH, REFERENCE,
    or VALUE). The function value is, by definition, an OUT access
    mode value.

    The data type is required and describes the type of parameter
    using either an SQL data type or a domain name.

    You cannot declare a function value as the LIST OF BYTE VARYING
    data type.