Use of message disposition notification

Hi,

I read in 3.5 for an injected agent:

    It SHOULD reject any proto-article which contains a header field
    deprecated for Netnews (see, for example, [RFC3798] (Hansen, T. and
    G. Vaudreuil, "Message Disposition Notification," May 2004.)).


How is it supposed to be used?  I read in RFC 3798 that it is used
to "report the disposition of a message after it has been successfully
delivered".  In our case, the message is rejected and not delivered.

Is it really here that RFC 3798 is to be referenced?  (And not USEFOR
or another RFC?)
If yes, could it be better explained?

-- 
Julien ÉLIE

« Rien, ce n'est pas rien ! La preuve, c'est que l'on peut le soustraire.
  Exemple : rien moins rien = moins que rien ! » (Raymond Devos)