Review of CONNEC MIME documents

At the IETF meeting in Oslo, I was asked to review some
CONNEC documents from a MIME viewpoint. Here is that review.
I am not a subscriber to the ietf-medfree mailing list,
so if you want me to see your comments on this message,
then include me in the recipient list for these comments.

draft-ietf-conneg-content-features-01.txt
-----------------------------------------

Section 3.1.1 first line contains the word "should". The
appearance of the word "should" in a standard is often
confusing. Do you mean "SHOULD". If so, you should spell it
in uppercase. If you do not mean "SHOULD" it might be
better to use some other wording, which cannot be confused
with the word "SHOULD".

Section 3.1.1 first paragraph last sentence "This is
possible but not recommended": This does not agree with the
recommendation in 3.1.2 to use "Content-Type: Multipart"
combined with another Content-Type in the
"Content-Features" header.

Section 3.1.2 perhaps you should specify that if the same
content-feature occurs on both an outer and an inner MIME
body part, then the inner feature applies, but that
features on outer body parts which are not repeated on
inner body parts will still apply to that inner body part.

Section 4 in general: See comment on
draft-ietf-conneg-feature-type-01.txt and the charset
parameter below.

Section 4.2 should perhaps be liased with the IETF groups
working on Internet Fax.

Section 4.6: Possibly the standard for Multipart/Related,
RFC 2387, should be references?

draft-ietf-conneg-feature-type-01.txt
-------------------------------------

The MIME standard (part 2) specifies: "In order to
eliminate such ambiguity and variations in the future, it
is strongly recommended that new user agents explicitly
specify a character set as a media type parameter in the
Content-Type header field."

It is a well-known problem with not specifying any
character set, especially since e-mail says that the
default character set is US-ASCII, while HTTP says that the
default character set is ISO-8859-1. If the standards were
redone today, the charset parameter should be mandatory for
all "Content-Type: Text"s. Because of this, it is not so
nice that the draft gives many examples where no charset is
specified, neither as a parameter to "Content-Type" nor in
the "Content-Features" header. Suggestion: Specify the
character set either in the "Content-Type: Text" or in the
"Content-Features" header.

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Jacob Palme <[email protected]> (Stockholm University and KTH)
for more info see URL: http://www.dsv.su.se/~jpalme