usefor-article-04 April 2001

6.19.1.3.  The posting-sender-parameter

   This parameter identifies the mailbox of the verified sender of the
   article (alternatively, it uses the token "verified" to indicate that
   at least any addr-spec in the Sender header of the article, or in the
   From header if the Sender header is absent, is correct).

        NOTE: An injecting agent is unlikely to be able to make use of
        this parameter except in cases where it is running on a machine
        which is aware of the user-space in which the posting agent is
        operating. This parameter should be used in preference to a
        posting-account-parameter in such situations.