VMS Help SET, HOST, /TN3270, Qualifiers  *Conan The Librarian (sorry for the slow response - running on an old VAX)

1 - /AUTHENTICATE

    Specifies that Kerberos authentication should be used for
    acquiring access to the remote node.

2 - /PORT

       /PORT=port

    Specifies the remote TCP port to use. The default is 23.

3 - /TERMINAL_TYPE

    Sets the terminal emulator to one of the following terminal
    types: VT100, VT200, VT300, VT400, VT500.