[Top] [All Lists]

Comment on the draft MIME Part 1 document

1993-04-22 05:21:22
RFC 1341++ is intended to be applicable also to (future Internet
standard) transport mechanisms with no 7-bit or line-length
restrictions.  I believe that for header fields in body-parts
8-bit characters is still not allowed, but at least in the
message body (of a body-part or of an unstructured message)
8-bit characters are not excluded by RFC 1341++.

These important facts are not at all reflected in the formal
grammer, although that should provide the most exact description
of MIME.  (The grammar is based on the formal grammer of RFC 822
which has explicit 7-bit restrictions in definitions used in the
RFC 1341++ grammar.)

I therefore suggest a few additions to the BNF rules:

          body-part = <"message" as defined in RFC 822,
                   with all header fields optional, and with the
                   specified delimiter not occurring anywhere in
                   the message body, either on a line by itself
                   or as a substring anywhere.>

Add to this definition: "... and with the RFC 822 restriction on
characters of the body to the range 0-127 removed"

By the way, there is a typo in this definition: Replace "=" by ":=".

          discard-text := *[*text CRLF]

The simplest way is I think to replace "text" in this definition
by a new term, say "utext", and add the definition:

            utext := <any character represented by one octet>
                          ; (0 - 255)

Olle Jarnefors                     Internet: 
Information Management Services        UUCP: ...!uunet!mcsun!sunic!kth!ojarnef
Royal Institute of Technology (KTH)  BITNET: ojarnef(_at_)sekth  Fax:+46 8 10 
25 10
S-100 44  Stockholm, Sweden           Phone: +46 8 790 71 26 (time zone +0200)