RFC 2530 (rfc2530) - Page 2 of 5


Indicating Supported Media Features Using Extensions to DSN and MDN



Alternative Format: Original Text Document



RFC 2530            Media Features using DSN and MDN          March 1999


3.  Extensions for use by DSN and MDN

   The following extension is available to both DSN [RFC 1894] and MDN
   [RFC 2298] messages.

   For a DSN message, the following per-recipient fields are defined
   (section 2.3 of [RFC 1894]).  For an MDN message, the following
   extension fields are defined (section 3.1 of [RFC 2298]).  Using the
   language of [RFC 2234]:

      extension-field    = media-features CRLF

      media-features     = "Media-Accept-Features" ":"
                            media-feature-tags
      media-feature-tags = 

   The  are defined in separate schema documents
   which MUST utilize the language described in [SYNTAX].  The schema
   MUST be registered following the registration requirements of
   [RFC 2506].

3.1.  Examples

   The following examples assume there is a schema document which
   defines the tags shown.

3.1.1.  Paper-size and Color

   Assuming there is a schema document which describes the tags paper-
   size and color, the following example is valid:

      Media-Accept-Features: (& (paper-size=a4) (color=binary) )

3.1.2.  UA-Media, Paper-size, and Color

   Assuming there is a schema document which describes the tags paper-
   size, color, and grey:

      Media-Accept-Features: (& (| (paper-size=a4) (paper-size=letter) )
        (| (& (color=grey) (dpi=200) (dpi-xyratio=200/100) )
        (& (color=limited) (dpi=200) (dpi-xy=200/100) ) )

4.  MTA Implmentation Recommendation

   If the recipient's MTA determines that a message cannot be processed,
   the recipient's MTA is strongly encouraged to reject the message with
   a status code of 5.6.1 [RFC 1893].  This status code may be returned



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