MDN disposition status

["McIntyre, Lloyd" <Lloyd.McIntyre@xxxxxxxxxxxxxx>]

We appear to be approaching consensus with regard to MDN disposition status
so allow me to propose some modifications and refinements.

Lloyd

Given the RFC 2298 disposition format
Disposition: action-mode/sending-mode; disposition-type/disposition-modifier


1. In the case of processing and or rendering failure:

a) If an entire MIME part cannot be rendered and reason for failure is not
fully understood or does not fit into one of a series of error-modifier
categories then disposition-type = processed/error may be appropriate.

Example
  disposition = automatic-action/MDN-sent-automatically; processed/error

b) If portion of a MIME part cannot be rendered and reason for failure is
not fully understood or does not fit into one of a series of descriptive
error-modifier categories then disposition-type = processed/error with page
identification information may be appropriate. 
  disposition-type = processed/error:pages

"pages" reflects totalpages and comma separate errorpages or errorpages 
   pages= totalpages=N,errorpages=a,b,c

   - "totalpages" reflects the total page count "N" within the MIME part. If
present, totalpages shall be the first of the pages parameters.
     totalpages is included when the MIME part is not page formatted by the
sender and does not include a page count. If present, it shall be the first
error modifier listed. This is the case when the MIME part is text/plain.
This becomes valuable when offramp gateways are involved and the offramping
occurs over services that do not guarantee message integrity, portions of
the message may not be delivery (e.g. PSTN fax). There is no need to include
totalpages when the page count of the MIME content is predetermined, as in
the case of an image/TIFF MIME content.

   - "errorpages=a,b,c", where a,b,c is a comma string of page numbers,
represents the pages not rendered. If totalpages is present then
errorpages=a,b,c shall be the second of the pages parameters.
 
Example
If the page count is not predetermined,
  disposition = automatic-action/MDN-sent-automatically;
processed/error:totalpages=10,errorpages=2,7
If the page count is predetermined,
  disposition = automatic-action/MDN-sent-automatically;
processed/error:errorpages=2,7

c) If an entire MIME part cannot be rendered and reason for failure is
understood and does fit into one of a series of error-modifier categories
then disposition-type = processed/error with a series of error-modifier is
suggested to better inform the sender for future interactions.
  disposition-type = processed/error:error-modifier

  error-modifier= 
     unsupported file format/
        - where the file format is not supported or recognized 
     unsupported compression/
        - where the compression type is not supported or recognized
     unsupported resolution/
        - where the resolution is not supported or recognized
     unsupported image size/
        - where the image size is not supported
     unsupported parameters/
        - where there may be a combination of unsupported encoding
parameters

Example
  disposition = automatic-action/MDN-sent-automatically;
processed/error:unsupported file format

d) If portion of a MIME part cannot be rendered and reason for failure is
understood and does fit into one of a series of error-modifier categories
then disposition-type = processed/error:pages,error-modifier is suggested to
better inform the sender for future interactions. When pages is present then
error-modifier shall be the comma separated second set of error parameters

Example
  disposition = automatic-action/MDN-sent-automatically;
processed/error:totalpages=10,errorpages=2,7,unsupported file format
or
  disposition = automatic-action/MDN-sent-automatically;
processed/error:errorpages=2,7,unsupported file format


2) In the case of processing and rendering with possible distortions then
the use disposition-type= dispatched with "warning" disposition modifier and
possibly a series of warning modifiers may be appropriate.

a) If an entire MIME part is rendered with possible image distortion and the
distortion is not fully understood or does not fit into one of a series of
warning-modifier categories then disposition-type = dispatched/warning may
be appropriate.
Example
  disposition = automatic-action/MDN-sent-automatically; dispatched/warning

b) If portion of a MIME part is rendered with possible image distortion and
reason for failure is not fully understood or does not fit into one of a
series of descriptive warning modifier categories then disposition-type =
dispatched/warning with page information may be appropriate. 
  disposition-type = processed/error:pages 

"pages" reflects totalpages and comma separate warningpages or warningpages 
   pages= totalpages=N,warningpages=a,b,c

   - "totalpages" reflects the total page count "N" within the MIME part. If
present, totalpages shall be the first of the pages parameters.
     The rational is same as for errors.

   - "warningpages=a,b,c", where a,b,c is a comma string of page numbers,
represents the pages rendered with possible distortion. If totalpages is
present then warningpages=a,b,c shall be the second of the pages parameters.

Example
If the page count is not predetermined,
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:totalpages=10,warningpages=2,7
or if the page count is predetermined,
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:warningpages=2,7

c) In the case of processing and rendering of an entire MIME part with
possible distortions for reasons understood, such as format transformations
or encoding transcoding, then the use of type-type= dispatched/warning with
a series of warning-modifiers is suggested to better inform the sender for
future interactions.
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:warning-modifier

warning-modifier=
   rendered as gray/
     - when a color image is processed but rendered as gray
   rendered at lower color fidelity/
     - when a color image is processed but rendered at a lower color quality
   rendered at lower resolution/
     - when the image is processed but rendered at lower resolution
   size scaled down to fit/
     - when the image is processed but scaled down with aspect ratio
retention to accommodate rendering
   size scaled down to fit with distortion/
     - when the image is processed but scaled down without aspect ratio
retention to accommodate rendering
   possible distortions due to encoder change/
     - when the image is transcoded to a different encoding, such as from a
lossless to a lossy encoding (e.g. JBIG color to JPEG) to accommodate
offramping  or down stream processing 
   possible distortions due to transmission errors/
     - when the image is subjected to offramp transmission errors 
   possible distortions due to file errors/
     - when image distortion is likely to result from inconsistent tag
values for tags such as XResolution, YResolution and ImageWidth;
PhotometricInterpretation, SamplesPerPixel, and BitsPerSample

Example
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:rendered as gray

d) In the case of processing and rendering portion of the MIME part with
possible distortions for reasons understood, such as format transformations
or encoding transcoding, then the use of type-type= dispatched/warning with
page indication and a series of warning-modifiers may be appropriate.
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:pages,warning-modifier


Example
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:totalpages=10,warningpages=2,7,rendered as gray
or 
  disposition = automatic-action/MDN-sent-automatically;
dispatched/warning:warningpages=2,7,rendered as gray

***********************************************
Lloyd McIntyre        lmcintyre@xxxxxxxxxxxxxx
Xerox Corp., Xerox Architecture Center
3400 Hillview Ave. Bldg. 1
Palo Alto, CA 94304
Tel: +1 650 813 6762   fax: +1 650 813 6860
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