VMS Help NCS Routines, NCS$CONVERT, Condition Values Returned  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    SS$_NORMAL         Normal successful completion.
    NCS$_NOT_CF        Name of identifier does not refer to a
                       conversion function.
    STR$_TRU           Successful completion. However, the resultant
                       string was truncated because the storage
                       allocation for the destination string was
                       inadequate.