message context
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... different ways. As explained in RFC 3458prop [1], the "message context"
of the message conveys information about the way the user expects to
interact with the message, such as which icon to display. RFC 3458prop ...
... message contexts properly identify such
video messages. This specification extends the Message-Context
header with one additional context ...
... Message-Context ...
...
This header is intended to be an indicator of message context only.
As such, it is only a hint and requires no behavior on the part of a
...
... Burger, E., Candell, E., Eliot, C., and G. Klyne, "Message Context for Internet Mail", RFC 3458prop, January 2003. ...