/sys$common/syshlp/helplib.hlb Sys Files, [SYSLIB], BACKUPSHR.EXE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The BACKUP shareable image, which is invoked by [SYSEXE]BACKUP.EXE
    and is used by other applications that invoke BACKUP using the
    BACKUP Application Program Interface (BACKUP API)