The index value of the vector element to return.

    Value:         A value greater than or equal to 1 and less than
                   or equal to 20
    Data type:     Unsigned longword
    Passing        By value
    mechanism:

    The following table shows the index values and how they map to
    vector elements and the information contained in each vector
    element.

    Index
    Value Information Returned

    1     Number of arguments in the vector
    2     Primary status code of the last SQL statement
    3     Number of FAO arguments to primary message
    4-20  Return status for follow-on messages, if any