format=flowed (was Re: [linux-elitists] Seperating Content from Presentation)

Gerald Oskoboiny
Wed Jun 9 21:33:04 PDT 2004

* Ben Finney <> [2004-05-31 15:28+1000]
> On 31-May-2004, Mike MacCana wrote:

> > Maillers shouldn't wrap at all. Wrapping is a terrible idea which
> > assumes one's audience:
> > 
> > 1. Reads their email in a monospaced font
> No, it doesn't assume this.  If the line-wrapped mail is rendered in the
> user's chosen font, it is no less readable if the lines are wrapped.
> > 2. In an eighty character wide terminal.
> Or wider.  This assumption is better than assuming the MUA somehow knows
> the difference between a line that should be automagically wrapped and
> one that shouldn't.
> HTML documents can assume that their lines will be wrapped, because in
> the cases where they shouldn't be wrapped there is markup to say so.
> Text documents (like email messages) cannot make that assumption.
> Remember, make the data smart, so the software can be simple.

RFC 2646 (The Text/Plain Format Parameter) addresses this problem
quite nicely, defining a format=flowed parameter for text/plain
documents which indicates that text may be reflowed.

    What is required is a format which is in all significant ways
    Text/Plain, and therefore is quite suitable for display as
    Text/Plain, and yet allows the sender to express to the receiver
    which lines can be considered a logical paragraph, and thus flowed
    (wrapped and joined) as appropriate.

    This memo proposes a new parameter to be used with Text/Plain, and,
    in the presence of this parameter, the use of trailing whitespace to
    indicate flowed lines.  This results in an encoding which appears as
    normal Text/Plain in older implementations, since it is in fact
    normal Text/Plain.


Basically, lines that have a trailing space are OK to reflow,
others are not.

Checking my email intake yesterday, the following MUAs seem to
generate messages with format=flowed:

    Apple Mail
    Mozilla Thunderbird
    Opera M2
    QUALCOMM Windows Eudora

I don't know how many of those actually reflow text using format=flowed.

Gerald Oskoboiny <>

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