ietf-822
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Re: Is Content-type an RFC822 "structured header"?

1999-05-23 10:39:42
At 10:43 21/05/99 GMT, Charles Lindsey wrote:

  Content-type: image/tiff; boundary=
    "longboundarystringwrappedtonextlinetolimitlinelength"

It is completely legal.

Fine, but that still does not establish _exactly_ where folding may occur.

I beg to differ, in this case, because RFC822 (cited directly by the MIME
document) describes the lexical analysis of structured header fields:

     3.1.4.  STRUCTURED FIELD BODIES

        To aid in the creation and reading of structured  fields,  the
        free  insertion   of linear-white-space (which permits folding
        by inclusion of CRLFs)  is  allowed  between  lexical  tokens.
        Rather  than  obscuring  the  syntax  specifications for these
        structured fields with explicit syntax for this  linear-white-
        space, the existence of another "lexical" analyzer is assumed.

and

        These symbols are:

                     -  individual special characters
                     -  quoted-strings
                     -  domain-literals
                     -  comments
                     -  atoms

Thus, folding is permitted between any pair of symbols indicated above.

This is currently of concern to me because I am writing the syntax for the
new USEFOR draft (RFC1036bis) and we need to spell it all out in the
syntax in DRUMS style.

Hmmm... that's hard work ;-)

#g

------------
Graham Klyne
(GK(_at_)ACM(_dot_)ORG)