Library /sys$common/syshlp/tcpip$ucp_help.hlb MOUNT, Qualifiers, /PROTECTION  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /PROTECTION=protections

    Optional. Default: /PROTECTION=(S:RWED,O:RWED,G:RWED,W:RWED).

    Protection code for the volume. If you omit a category, the
    client denies access to that category of user.

    Applied only on the first mount of an NFS device and ignored with
    subsequent mounts on that device.

    Restrictions: Requires OPER privilege.