VMS Help MACRO, /MIGRATION, Qualifiers, /WARN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /WARN=[[option]...]
       /NOWARN

    Turns off all informational level or warning level messages. Both
    are on by default.

    Option     Description

    INFO       Turns on all informational level messages
    NOINFO     Turns off all informational level messages
    WARN       Turns on all informational and warning level messages
    NOWARN     Turns off all informational and warning level messages