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

    LBR$_DUPKEY        Index already contains the specified key.
    LBR$_ILLCTL        Specified library control index not valid.
    LBR$_INVRFA        Specified RFA does not point to valid data.
    LBR$_LIBNOTOPN     Specified library not open.
    LBR$_UPDURTRAV     LBR$INSERT_KEY was called by the user-defined
                       routine specified in LBR$SEARCH or LBR$GET_
                       INDEX.