VMS Help PRODUCT, SHOW, HISTORY, Qualifiers, /USER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /USER=(username[,...])

    Displays information about the products installed, configured, or
    removed by the specified user.

    Parentheses (())  are optional only when you specify a single
    user name. They are required when you specify multiple user
    names.