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

    Creates or allows you to replace a secondary password. The
    procedure is the same as setting your primary password.

    Once a secondary password has been established, you will receive
    two PASSWORD: prompts when logging in. The primary password
    should be typed in first, followed by the secondary password.

    Secondary passwords make it possible to set up an account that
    requires two different people to access it. Each person knows one
    of the two passwords, and both passwords are required to log in
    successfully.

    To remove your secondary password, press Return when SET
    PASSWORD/SECONDARY prompts you for a new password and
    verification. After you do this, you will receive a single
    PASSWORD: prompt when logging in. If you remove the secondary
    password, your system manager must restore it.

    The /SECONDARY and /SYSTEM qualifiers are incompatible.