formail address precedence?

Does anyone know the RFC that defines the precedence of the return
addresses generated by:

    formail -rzx

and:

    formail -rtzx

        Thanks,

        John

-- 

John Conover, conover(_at_)rahul(_dot_)net, http://www.rahul.net/~conover

_______________________________________________
procmail mailing list
procmail(_at_)lists(_dot_)RWTH-Aachen(_dot_)DE
http://MailMan.RWTH-Aachen.DE/mailman/listinfo/procmail