Mozilla: Format=Flowed Mini-FAQ
Draft 4, 19 May 2003. Changes to #4, #5, #6
1. Why doesn't mozilla wrap lines at 72 characters?
You set line wrapping to 72 characters in preferences, and
while you're composing a message everything seems to be fine. But after
you sent the message, it looks as if Mozilla forgot the line wrapping
completely. What's going on? Actually, Mozilla does indeed break lines
according to the settings in Edit -> Preferences -> Mail&Newsgroups
-> Compose: Standard for Mozilla is to break lines at 72 characters
(Classic Netscape Communicator style). You can see for yourself: Select
a message that seems to have no line wrapping and check out the source
by hitting Ctrl+U. You will see that Mozilla breaks lines just fine, but
Mozilla has a new way of displaying messages that are sent in an Internet
standard called format=flowed.
2. What happened to the old-style ">" that used to appear
when I replied to a message?
Along with format=flowed comes increased use of excerpt
bars in plain text messages. Again, look at the source of a message.
The ">"s are still there but replaced by Mozilla when viewing a
message.
3. How does Format=Flowed work?
The way format=flowed works is by sending your mail
wrapped and with normal quote characters, just like before (as you
notice when you look at the source). The only difference is that whenever
text is wrapped, a single space is added at the end of the line and
the Content-Type header looks similar to this:
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
The combination of the single space and the header info allows
a format=flowed capable mail/news program such as Mozilla to reformat
the lines according to the window width - it doesn't matter how wide
or narrow a window is, text is always displayed legible without ugly 'combing'
effects that usually affected users on small displays. That is also why
excerpt bars are used instead of ">": the bars adjust themselves
on the fly to your window width, inserting or removing ">" in such
a dynamic environment would be very slow and clumsy.
4. How does Format=Flowed affect Non-Format=Flowed Readers?
Ideally, Mail/Newsreaders not capable of displaying format=flowed
messages should not be affected at all, because the only difference
for a simple mailer should be the extra single space at the end of each
line. So they should be presented with normal line wraps and the
normal ">". But the current implementation of format=flowed in Mozilla
might pose problems, because the format=flowed standard requires some changes
on what you wrote.
Lines starting with a space receive an extra identation when the message
is sent. This may, for example, cause strange effects with ASCII drawings
or list-style texts. Also quote symbols at the beginning of a line will
be padded by a space (this will invalidate the special treatment of quoted
material, e.g. coloring). The same is true for the word from at the beginning
of a line. Whenever you have ">" or "From " at the beginning of a line
it will be space-stuffed. This is not visible in the editor. If you want
to mark quotes by hand, you must use paste as quotation.
Also have a look at the bugs mentioned below, some of those, e.g. bug 155015,
bug 161968,
bug
114954 and bug 144998, also affect
users of "classic" mail/news readers.
5. What are the advantages of using Format=Flowed?
Properly used, format=flowed has a lot to offer over
simple plaintext: Legible mail on small displays, dynamic adjustments
of window widths won't result in nasty combing effects, unambiguous
marking of quoted text (no more guessing for the program and the user where
the different quote levels begin).
6. How do I deactivate format=flowed?
If you do not want to use Format=Flowed because you always
read mails with a maximized window on a high resolution or you want
to avoid the problems with the current implementation of format=flowed
you should add the following line to your prefs.js:
user_pref("mailnews.display.disable_format_flowed_support", true);
user_pref("mailnews.send_plaintext_flowed", false);
(the first user_pref will disable the display of format=flowed
emails/news postings, the second user_pref completely disables format=flowed,
i.e. also the sending in this format. You must use both user_prefs to
completely deactivate format=flowed)
7. Where can I find more information about format=flowed?
RFC: http://www.ietf.org/rfc/rfc2646.txt
For an overview of Bugs dealing with Format=Flowed: bug 168420
8. Known Problems with Mozilla's current format=flowed
implementation
Empty lines under quotes are doubled: bug 144998
Mail editor space-stuffs quote prefixes in pasted text: bug
114954
This means that any quote symbol you type manually
will be space-stuffed and hence not display as a quote. This might happen
if you break a quoted line into pieces and want to add the symbol. You
must use paste as quotation to avoid this problem.
Need pref to set message view pane width separate from window
width: bug
71110
[RFE] UI option for disabling format=flowed: bug 86607
Format=flowed message generation must follow CJK line-breaking
conventions: bug
26734
Editing draft (or other plain text message as new)
loses flowed quoting information: bug
104348
Attachment with format=flowed is displayed with <div>:
bug
121297
Paragraph breaks in format=flowed MIME text not displayed
properly: bug
141095
Format=flowed and lines with 2+ spaces at the end:
bug 155015
Wrapping information lost on "Edit as new", "Edit draft"
(RFC 2646 format=flowed): bug
155622
Wrapping quoted lines get wrong quote status: bug 161968
(fixed 2002-10-08)
In versions before this was fixed (including all Netscape
versions up to and including 7.0x and Mozilla <=1.2b) when you applied
rewrapping to quoted text, the quote symbols were space-stuffed and hence
do not display as quotes anymore.
Space added to indented line when sending message: bug 141983
To avoid this make sure the the complete text block where
you need to indent something does not start in the first column. If
you try to underline something in a quoted line above, this will also
be moved for people not using f=f.