At 05:46 PM 1/18/02 -0500, The IESG wrote:
The IESG has received a request to consider Message Disposition
Notification <draft-vaudreuil-mdnbis-01.txt> as a Draft Standard,
obsoleting RFC2298, currently a Proposed Standard.
My apologies for this late comment...
[[[
2.2 The Disposition-Notification-Options Header
Future extensions to this specification may require that information
be supplied to the recipient's MUA for additional control over how and
what MDNs are generated. The Disposition-Notification-Options header
provides an extensible mechanism for such information. The syntax of
this header is
Disposition-Notification-Options =
"Disposition-Notification-Options" ":"
disposition-notification-parameters
disposition-notification-parameters = parameter *(";" parameter)
parameter = attribute "=" importance "," value *("," value)
importance = "required" / "optional"
]]]
The syntax of "parameter" requires that a value always be present, even
when none is needed. I have been involved in the design of MDN extensions
for which it has been necessary to "invent" a dummy value to satisfy the
syntax; e.g.
[[[
Disposition-Notification-Options:
Alternative-not-available=required,(TRUE)
]]]
Here, the value '(TRUE)' is a dummy that serves no purpose other than to
satisfy the above syntax.
An alternative syntax might be:
[[[
parameter = attribute "=" importance *("," value)
]]]
in which case the above example might be:
[[[
Disposition-Notification-Options:
Alternative-not-available=required
]]]
#g
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Graham Klyne Baltimore Technologies
Strategic Research Content Security Group
<Graham(_dot_)Klyne(_at_)Baltimore(_dot_)com> <http://www.mimesweeper.com>
<http://www.baltimore.com>
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