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File: emacs-mime,  Node: Top,  Next: Decoding and Viewing,  Up: (dir)

Emacs MIME

This manual documents the libraries used to compose and display MIME

   This manual is directed at users who want to modify the behavior of
the MIME encoding/decoding process or want a more detailed picture of
how the Emacs MIME library works, and people who want to write
functions and commands that manipulate MIME elements.

   MIME is short for "Multipurpose Internet Mail Extensions".  This
standard is documented in a number of RFCs; mainly RFC2045 (Format of
Internet Message Bodies), RFC2046 (Media Types), RFC2047 (Message
Header Extensions for Non-ASCII Text), RFC2048 (Registration
Procedures), RFC2049 (Conformance Criteria and Examples).  It is highly
recommended that anyone who intends writing MIME-compliant software
read at least RFC2045 and RFC2047.

   This file documents the Emacs MIME interface functionality.

   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
2007, 2008, 2009 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.3 or any later version published by the Free Software
     Foundation; with no Invariant Sections, with the Front-Cover texts
     being "A GNU Manual", and with the Back-Cover Texts as in (a)
     below.  A copy of the license is included in the section entitled
     "GNU Free Documentation License".

     (a) The FSF's Back-Cover Text is: "You have the freedom to copy and
     modify this GNU manual.  Buying copies from the FSF supports it in
     developing GNU and promoting software freedom."

* Menu:

* Decoding and Viewing::  A framework for decoding and viewing.
* Composing::             MML; a language for describing MIME parts.
* Interface Functions::   An abstraction over the basic functions.
* Basic Functions::       Utility and basic parsing functions.
* Standards::             A summary of RFCs and working documents used.
* GNU Free Documentation License:: The license for this documentation.
* Index::                 Function and variable index.

File: emacs-mime,  Node: Decoding and Viewing,  Next: Composing,  Prev: Top,  Up: Top

1 Decoding and Viewing

This chapter deals with decoding and viewing MIME messages on a higher

   The main idea is to first analyze a MIME article, and then allow
other programs to do things based on the list of "handles" that are
returned as a result of this analysis.

* Menu:

* Dissection::             Analyzing a MIME message.
* Non-MIME::               Analyzing a non-MIME message.
* Handles::                Handle manipulations.
* Display::                Displaying handles.
* Display Customization::  Variables that affect display.
* Files and Directories::  Saving and naming attachments.
* New Viewers::            How to write your own viewers.

File: emacs-mime,  Node: Dissection,  Next: Non-MIME,  Up: Decoding and Viewing

1.1 Dissection

The `mm-dissect-buffer' is the function responsible for dissecting a
MIME article.  If given a multipart message, it will recursively
descend the message, following the structure, and return a tree of MIME
handles that describes the structure of the message.

File: emacs-mime,  Node: Non-MIME,  Next: Handles,  Prev: Dissection,  Up: Decoding and Viewing

1.2 Non-MIME

Gnus also understands some non-MIME attachments, such as postscript,
uuencode, binhex, yenc, shar, forward, gnatsweb, pgp, diff.  Each of
these features can be disabled by add an item into
`mm-uu-configure-list'.  For example,

     (require 'mm-uu)
     (add-to-list 'mm-uu-configure-list '(pgp-signed . disabled))

     PostScript file.

     Uuencoded file.

     Binhex encoded file.

     Yenc encoded file.

     Shar archive file.

     Non-MIME forwarded message.

     Gnatsweb attachment.

     PGP signed clear text.

     PGP encrypted clear text.

     PGP public keys.

     Emacs source code.  This item works only in the groups matching

     Patches.  This is intended for groups where diffs of committed
     files are automatically sent to.  It only works in groups matching

     Slrn-style verbatim marks.

     LaTeX documents.  It only works in groups matching

   Some inlined non-MIME attachments are displayed using the face
`mm-uu-extract'.  By default, no MIME button for these parts is
displayed.  You can force displaying a button using `K b'
(`gnus-summary-display-buttonized') or add `text/x-verbatim' to
`gnus-buttonized-mime-types', *Note MIME Commands: (gnus)MIME Commands.

File: emacs-mime,  Node: Handles,  Next: Display,  Prev: Non-MIME,  Up: Decoding and Viewing

1.3 Handles

A MIME handle is a list that fully describes a MIME component.

   The following macros can be used to access elements in a handle:

     Return the buffer that holds the contents of the undecoded MIME

     Return the parsed `Content-Type' of the part.

     Return the `Content-Transfer-Encoding' of the part.

     Return the object that can be used to remove the displayed part
     (if it has been displayed).

     Set the undisplayer object.

     Return the parsed `Content-Disposition' of the part.

     Returns the handle(s) referred to by `Content-ID'.

File: emacs-mime,  Node: Display,  Next: Display Customization,  Prev: Handles,  Up: Decoding and Viewing

1.4 Display

Functions for displaying, removing and saving.

     Display the part.

     Remove the part (if it has been displayed).

     Say whether a MIME type can be displayed inline.

     Say whether a MIME type should be displayed automatically.

     Free all resources occupied by a part.

     Offer to save the part in a file.

     Offer to pipe the part to some process.

     Prompt for a mailcap method to use to view the part.

File: emacs-mime,  Node: Display Customization,  Next: Files and Directories,  Prev: Display,  Up: Decoding and Viewing

1.5 Display Customization

     This is an alist where the key is a MIME type, the second element
     is a function to display the part "inline" (i.e., inside Emacs),
     and the third element is a form to be `eval'ed to say whether the
     part can be displayed inline.

     This variable specifies whether a part _can_ be displayed inline,
     and, if so, how to do it.  It does not say whether parts are
     _actually_ displayed inline.

     This, on the other hand, says what types are to be displayed
     inline, if they satisfy the conditions set by the variable above.
     It's a list of MIME media types.

     This is a list of types that are to be displayed "automatically",
     but only if the above variable allows it.  That is, only inlinable
     parts can be displayed automatically.

     This is a list of types that will be displayed automatically in an
     external viewer.

     This is a list of media types for which the external viewer will
     not be killed when selecting a different article.

     Some MIME agents create parts that have a content-disposition of
     `attachment'.  This variable allows overriding that disposition and
     displaying the part inline.  (Note that the disposition is only
     overridden if we are able to, and want to, display the part

     List of MIME types that are discouraged when viewing
     `multipart/alternative'.  Viewing agents are supposed to view the
     last possible part of a message, as that is supposed to be the
     richest.  However, users may prefer other types instead, and this
     list says what types are most unwanted.  If, for instance,
     `text/html' parts are very unwanted, and `text/richtext' parts are
     somewhat unwanted, you could say something like:

          (setq mm-discouraged-alternatives
                '("text/html" "text/richtext")
                (remove "text/html" mm-automatic-display))

     Adding `"image/.*"' might also be useful.  Spammers use images as
     the preferred part of `multipart/alternative' messages, so you
     might not notice there are other parts.  See also
     `gnus-buttonized-mime-types', *note MIME Commands: (gnus)MIME
     Commands.  After adding `"multipart/alternative"' to
     `gnus-buttonized-mime-types' you can choose manually which
     alternative you'd like to view.  For example, you can set those
     variables like:

          (setq gnus-buttonized-mime-types
                '("multipart/alternative" "multipart/signed")
                '("text/html" "image/.*"))

     In this case, Gnus will display radio buttons for such a kind of
     spam message as follows:

          1.  (*) multipart/alternative  ( ) image/gif

          2.  (*) text/plain          ( ) text/html

     When displaying inline images that are larger than the window,
     Emacs does not enable scrolling, which means that you cannot see
     the whole image.  To prevent this, the library tries to determine
     the image size before displaying it inline, and if it doesn't fit
     the window, the library will display it externally (e.g. with
     `ImageMagick' or `xv').  Setting this variable to `t' disables
     this check and makes the library display all inline images as
     inline, regardless of their size.

     `mm-inlined-types' may include regular expressions, for example to
     specify that all `text/.*' parts be displayed inline.  If a user
     prefers to have a type that matches such a regular expression be
     treated as an attachment, that can be accomplished by setting this
     variable to a list containing that type.  For example assuming
     `mm-inlined-types' includes `text/.*', then including `text/html'
     in this variable will cause `text/html' parts to be treated as

     This selects the function used to render HTML.  The predefined
     renderers are selected by the symbols `w3', `w3m'(1), `links',
     `lynx', `w3m-standalone' or `html2text'.  If `nil' use an external
     viewer.  You can also specify a function, which will be called
     with a MIME handle as the argument.

     Some HTML mails might have the trick of spammers using `<img>'
     tags.  It is likely to be intended to verify whether you have read
     the mail.  You can prevent your personal informations from leaking
     by setting this option to `nil' (which is the default).  It is
     currently ignored by Emacs/w3.  For emacs-w3m, you may use the
     command `t' on the image anchor to show an image even if it is

     A regular expression that matches safe URL names, i.e. URLs that
     are unlikely to leak personal information when rendering HTML
     email (the default value is `\\`cid:').  If `nil' consider all
     URLs safe.

     You can use emacs-w3m command keys in the inlined text/html part by
     setting this option to non-`nil'.  The default value is `t'.

     The program used to start an external terminal.

     Indicate whether external MIME handlers should be used.

     If `t', all defined external MIME handlers are used.  If `nil',
     files are saved to disk (`mailcap-save-binary-file').  If it is
     the symbol `ask', you are prompted before the external MIME
     handler is invoked.

     When you launch an attachment through mailcap (*note mailcap::) an
     attempt is made to use a safe viewer with the safest options--this
     isn't the case if you save it to disk and launch it in a different
     way (command line or double-clicking).  Anyhow, if you want to be
     sure not to launch any external programs, set this variable to
     `nil' or `ask'.

   ---------- Footnotes ----------

   (1) See `' for more information about

   (2) The command `T' will load all images.  If you have set the
option `w3m-key-binding' to `info', use `i' or `I' instead.

File: emacs-mime,  Node: Files and Directories,  Next: New Viewers,  Prev: Display Customization,  Up: Decoding and Viewing

1.6 Files and Directories

     The default directory for saving attachments.  If `nil' use

     Directory for storing temporary files.

     A list of functions used for rewriting file names of MIME parts.
     Each function is applied successively to the file name.
     Ready-made functions include

          Delete all control characters.

          Delete characters that could have unintended consequences
          when used with flawed shell scripts, i.e. `|', `>' and `<';
          and `-', `.' as the first character.

          Remove all whitespace.

          Remove leading and trailing whitespace.

          Collapse multiple whitespace characters.

          Replace whitespace with underscores.  Set the variable
          `mm-file-name-replace-whitespace' to any other string if you
          do not like underscores.

     The standard Emacs functions `capitalize', `downcase', `upcase'
     and `upcase-initials' might also prove useful.

     List of functions used for rewriting the full file names of MIME
     parts.  This is used when viewing parts externally, and is meant
     for transforming the absolute name so that non-compliant programs
     can find the file where it's saved.

File: emacs-mime,  Node: New Viewers,  Prev: Files and Directories,  Up: Decoding and Viewing

1.7 New Viewers

Here's an example viewer for displaying `text/enriched' inline:

     (defun mm-display-enriched-inline (handle)
       (let (text)
           (mm-insert-part handle)
             (enriched-decode (point-min) (point-max))
             (setq text (buffer-string))))
         (mm-insert-inline handle text)))

   We see that the function takes a MIME handle as its parameter.  It
then goes to a temporary buffer, inserts the text of the part, does some
work on the text, stores the result, goes back to the buffer it was
called from and inserts the result.

   The two important helper functions here are `mm-insert-part' and
`mm-insert-inline'.  The first function inserts the text of the handle
in the current buffer.  It handles charset and/or content transfer
decoding.  The second function just inserts whatever text you tell it
to insert, but it also sets things up so that the text can be
"undisplayed" in a convenient manner.

File: emacs-mime,  Node: Composing,  Next: Interface Functions,  Prev: Decoding and Viewing,  Up: Top

2 Composing

Creating a MIME message is boring and non-trivial.  Therefore, a
library called `mml' has been defined that parses a language called MML
(MIME Meta Language) and generates MIME messages.

   The main interface function is `mml-generate-mime'.  It will examine
the contents of the current (narrowed-to) buffer and return a string
containing the MIME message.

* Menu:

* Simple MML Example::             An example MML document.
* MML Definition::                 All valid MML elements.
* Advanced MML Example::           Another example MML document.
* Encoding Customization::         Variables that affect encoding.
* Charset Translation::            How charsets are mapped from MULE to MIME.
* Conversion::                     Going from MIME to MML and vice versa.
* Flowed text::                    Soft and hard newlines.

File: emacs-mime,  Node: Simple MML Example,  Next: MML Definition,  Up: Composing

2.1 Simple MML Example

Here's a simple `multipart/alternative':

     <#multipart type=alternative>
     This is a plain text part.
     <#part type=text/enriched>
     <center>This is a centered enriched part</center>

   After running this through `mml-generate-mime', we get this:

     Content-Type: multipart/alternative; boundary="=-=-="


     This is a plain text part.

     Content-Type: text/enriched

     <center>This is a centered enriched part</center>


File: emacs-mime,  Node: MML Definition,  Next: Advanced MML Example,  Prev: Simple MML Example,  Up: Composing

2.2 MML Definition

The MML language is very simple.  It looks a bit like an SGML
application, but it's not.

   The main concept of MML is the "part".  Each part can be of a
different type or use a different charset.  The way to delineate a part
is with a `<#part ...>' tag.  Multipart parts can be introduced with
the `<#multipart ...>' tag.  Parts are ended by the `<#/part>' or
`<#/multipart>' tags.  Parts started with the `<#part ...>' tags are
also closed by the next open tag.

   There's also the `<#external ...>' tag.  These introduce
`external/message-body' parts.

   Each tag can contain zero or more parameters on the form
`parameter=value'.  The values may be enclosed in quotation marks, but
that's not necessary unless the value contains white space.  So
`filename=/home/user/#hello$^yes' is perfectly valid.

   The following parameters have meaning in MML; parameters that have no
meaning are ignored.  The MML parameter names are the same as the MIME
parameter names; the things in the parentheses say which header it will
be used in.

     The MIME type of the part (`Content-Type').

     Use the contents of the file in the body of the part

     The contents of the body of the part are to be encoded in the
     character set specified (`Content-Type'). *Note Charset

     Might be used to suggest a file name if the part is to be saved to
     a file (`Content-Type').

     Valid values are `inline' and `attachment' (`Content-Disposition').

     Valid values are `7bit', `8bit', `quoted-printable' and `base64'
     (`Content-Transfer-Encoding'). *Note Charset Translation::.

     A description of the part (`Content-Description').

     RFC822 date when the part was created (`Content-Disposition').

     RFC822 date when the part was modified (`Content-Disposition').

     RFC822 date when the part was read (`Content-Disposition').

     Who to encrypt/sign the part to.  This field is used to override
     any auto-detection based on the To/CC headers.

     Identity used to sign the part.  This field is used to override the
     default key used.

     The size (in octets) of the part (`Content-Disposition').

     What technology to sign this MML part with (`smime', `pgp' or

     What technology to encrypt this MML part with (`smime', `pgp' or

   Parameters for `text/plain':

     Formatting parameter for the text, valid values include `fixed'
     (the default) and `flowed'.  Normally you do not specify this
     manually, since it requires the textual body to be formatted in a
     special way described in RFC 2646.  *Note Flowed text::.

   Parameters for `application/octet-stream':

     Type of the part; informal--meant for human readers

   Parameters for `message/external-body':

     A word indicating the supported access mechanism by which the file
     may be obtained.  Values include `ftp', `anon-ftp', `tftp',
     `localfile', and `mailserver'.  (`Content-Type'.)

     The RFC822 date after which the file may no longer be fetched.

     The size (in octets) of the file.  (`Content-Type'.)

     Valid values are `read' and `read-write' (`Content-Type').

   Parameters for `sign=smime':

     File containing key and certificate for signer.

   Parameters for `encrypt=smime':

     File containing certificate for recipient.

File: emacs-mime,  Node: Advanced MML Example,  Next: Encoding Customization,  Prev: MML Definition,  Up: Composing

2.3 Advanced MML Example

Here's a complex multipart message.  It's a `multipart/mixed' that
contains many parts, one of which is a `multipart/alternative'.

     <#multipart type=mixed>
     <#part type=image/jpeg filename=~/rms.jpg disposition=inline>
     <#multipart type=alternative>
     This is a plain text part.
     <#part type=text/enriched name=enriched.txt>
     <center>This is a centered enriched part</center>
     This is a new plain text part.
     <#part disposition=attachment>
     This plain text part is an attachment.

   And this is the resulting MIME message:

     Content-Type: multipart/mixed; boundary="=-=-="


     Content-Type: image/jpeg;
     Content-Disposition: inline;
     Content-Transfer-Encoding: base64


     Content-Type: multipart/alternative; boundary="==-=-="


     This is a plain text part.

     Content-Type: text/enriched;

     <center>This is a centered enriched part</center>



     This is a new plain text part.

     Content-Disposition: attachment

     This plain text part is an attachment.


File: emacs-mime,  Node: Encoding Customization,  Next: Charset Translation,  Prev: Advanced MML Example,  Up: Composing

2.4 Encoding Customization

     Mapping from MIME charset to encoding to use.  This variable is
     usually used except, e.g., when other requirements force a specific
     encoding (digitally signed messages require 7bit encodings).  The
     default is

          ((iso-2022-jp . 7bit)
           (iso-2022-jp-2 . 7bit)
           (utf-16 . base64)
           (utf-16be . base64)
           (utf-16le . base64))

     As an example, if you do not want to have ISO-8859-1 characters
     quoted-printable encoded, you may add `(iso-8859-1 . 8bit)' to
     this variable.  You can override this setting on a per-message
     basis by using the `encoding' MML tag (*note MML Definition::).

     Prioritize coding systems to use for outgoing messages.  The
     default is `nil', which means to use the defaults in Emacs, but is
     `(iso-8859-1 iso-2022-jp iso-2022-jp-2 shift_jis utf-8)' when
     running Emacs in the Japanese language environment.  It is a list
     of coding system symbols (aliases of coding systems are also
     allowed, use `M-x describe-coding-system' to make sure you are
     specifying correct coding system names).  For example, if you have
     configured Emacs to prefer UTF-8, but wish that outgoing messages
     should be sent in ISO-8859-1 if possible, you can set this
     variable to `(iso-8859-1)'.  You can override this setting on a
     per-message basis by using the `charset' MML tag (*note MML

     As different hierarchies prefer different charsets, you may want
     to set `mm-coding-system-priorities' according to the hierarchy in
     Gnus.  Here's an example:

          (add-to-list 'gnus-newsgroup-variables 'mm-coding-system-priorities)
          (setq gnus-parameters
                 ;; Some charsets are just examples!
                 '(("^cn\\." ;; Chinese
                     '(iso-8859-1 cn-big5 chinese-iso-7bit utf-8)))
                   ("^cz\\.\\|^pl\\." ;; Central and Eastern European
                    (mm-coding-system-priorities '(iso-8859-2 utf-8)))
                   ("^de\\." ;; German language
                    (mm-coding-system-priorities '(iso-8859-1 iso-8859-15 utf-8)))
                   ("^fr\\." ;; French
                    (mm-coding-system-priorities '(iso-8859-15 iso-8859-1 utf-8)))
                   ("^fj\\." ;; Japanese
                     '(iso-8859-1 iso-2022-jp iso-2022-jp-2 shift_jis utf-8)))
                   ("^ru\\." ;; Cyrillic
                     '(koi8-r iso-8859-5 iso-8859-1 utf-8))))

     Mapping from MIME types to encoding to use.  This variable is
     usually used except, e.g., when other requirements force a safer
     encoding (digitally signed messages require 7bit encoding).
     Besides the normal MIME encodings, `qp-or-base64' may be used to
     indicate that for each case the most efficient of quoted-printable
     and base64 should be used.

     `qp-or-base64' has another effect.  It will fold long lines so that
     MIME parts may not be broken by MTA.  So do `quoted-printable' and

     Note that it affects body encoding only when a part is a raw
     forwarded message (which will be made by
     `gnus-summary-mail-forward' with the arg 2 for example) or is
     neither the `text/*' type nor the `message/*' type.  Even though
     in those cases, you can override this setting on a per-message
     basis by using the `encoding' MML tag (*note MML Definition::).

     When this is non-`nil', it means that textual parts are encoded as
     quoted-printable if they contain lines longer than 76 characters or
     starting with "From " in the body.  Non-7bit encodings (8bit,
     binary) are generally disallowed.  This reduce the probability
     that a non-8bit clean MTA or MDA changes the message.  This should
     never be set directly, but bound by other functions when necessary
     (e.g., when encoding messages that are to be digitally signed).

File: emacs-mime,  Node: Charset Translation,  Next: Conversion,  Prev: Encoding Customization,  Up: Composing

2.5 Charset Translation

During translation from MML to MIME, for each MIME part which has been
composed inside Emacs, an appropriate charset has to be chosen.

   If you are running a non-MULE Emacs, this process is simple: If the
part contains any non-ASCII (8-bit) characters, the MIME charset given
by `mail-parse-charset' (a symbol) is used.  (Never set this variable
directly, though.  If you want to change the default charset, please
consult the documentation of the package which you use to process MIME
messages.  *Note Various Message Variables: (message)Various Message
Variables, for example.)  If there are only ASCII characters, the MIME
charset US-ASCII is used, of course.

   Things are slightly more complicated when running Emacs with MULE
support.  In this case, a list of the MULE charsets used in the part is
obtained, and the MULE charsets are translated to MIME charsets by
consulting the table provided by Emacs itself or the variable
`mm-mime-mule-charset-alist' for XEmacs.  If this results in a single
MIME charset, this is used to encode the part.  But if the resulting
list of MIME charsets contains more than one element, two things can
happen: If it is possible to encode the part via UTF-8, this charset is
used.  (For this, Emacs must support the `utf-8' coding system, and the
part must consist entirely of characters which have Unicode
counterparts.)  If UTF-8 is not available for some reason, the part is
split into several ones, so that each one can be encoded with a single
MIME charset.  The part can only be split at line boundaries,
though--if more than one MIME charset is required to encode a single
line, it is not possible to encode the part.

   When running Emacs with MULE support, the preferences for which
coding system to use is inherited from Emacs itself.  This means that
if Emacs is set up to prefer UTF-8, it will be used when encoding
messages.  You can modify this by altering the
`mm-coding-system-priorities' variable though (*note Encoding

   The charset to be used can be overridden by setting the `charset'
MML tag (*note MML Definition::) when composing the message.

   The encoding of characters (quoted-printable, 8bit etc) is orthogonal
to the discussion here, and is controlled by the variables
`mm-body-charset-encoding-alist' and
`mm-content-transfer-encoding-defaults' (*note Encoding

File: emacs-mime,  Node: Conversion,  Next: Flowed text,  Prev: Charset Translation,  Up: Composing

2.6 Conversion

A (multipart) MIME message can be converted to MML with the
`mime-to-mml' function.  It works on the message in the current buffer,
and substitutes MML markup for MIME boundaries.  Non-textual parts do
not have their contents in the buffer, but instead have the contents in
separate buffers that are referred to from the MML tags.

   An MML message can be converted back to MIME by the `mml-to-mime'

   These functions are in certain senses "lossy"--you will not get back
an identical message if you run `mime-to-mml' and then `mml-to-mime'.
Not only will trivial things like the order of the headers differ, but
the contents of the headers may also be different.  For instance, the
original message may use base64 encoding on text, while `mml-to-mime'
may decide to use quoted-printable encoding, and so on.

   In essence, however, these two functions should be the inverse of
each other.  The resulting contents of the message should remain
equivalent, if not identical.

File: emacs-mime,  Node: Flowed text,  Prev: Conversion,  Up: Composing

2.7 Flowed text

The Emacs MIME library will respect the `use-hard-newlines' variable
(*note Hard and Soft Newlines: (emacs)Hard and Soft Newlines.) when
encoding a message, and the "format=flowed" Content-Type parameter when
decoding a message.

   On encoding text, regardless of `use-hard-newlines', lines
terminated by soft newline characters are filled together and wrapped
after the column decided by `fill-flowed-encode-column'.  Quotation
marks (matching `^>* ?') are respected.  The variable controls how the
text will look in a client that does not support flowed text, the
default is to wrap after 66 characters.  If hard newline characters are
not present in the buffer, no flow encoding occurs.

   On decoding flowed text, lines with soft newline characters are
filled together and wrapped after the column decided by
`fill-flowed-display-column'.  The default is to wrap after

     If non-`nil' a format=flowed article will be displayed flowed.

File: emacs-mime,  Node: Interface Functions,  Next: Basic Functions,  Prev: Composing,  Up: Top

3 Interface Functions

The `mail-parse' library is an abstraction over the actual low-level
libraries that are described in the next chapter.

   Standards change, and so programs have to change to fit in the new
mold.  For instance, RFC2045 describes a syntax for the `Content-Type'
header that only allows ASCII characters in the parameter list.
RFC2231 expands on RFC2045 syntax to provide a scheme for continuation
headers and non-ASCII characters.

   The traditional way to deal with this is just to update the library
functions to parse the new syntax.  However, this is sometimes the wrong
thing to do.  In some instances it may be vital to be able to understand
both the old syntax as well as the new syntax, and if there is only one
library, one must choose between the old version of the library and the
new version of the library.

   The Emacs MIME library takes a different tack.  It defines a series
of low-level libraries (`rfc2047.el', `rfc2231.el' and so on) that
parses strictly according to the corresponding standard.  However,
normal programs would not use the functions provided by these libraries
directly, but instead use the functions provided by the `mail-parse'
library.  The functions in this library are just aliases to the
corresponding functions in the latest low-level libraries.  Using this
scheme, programs get a consistent interface they can use, and library
developers are free to create write code that handles new standards.

   The following functions are defined by this library:

     Parse a `Content-Type' header and return a list on the following

           (attribute1 . value1)
           (attribute2 . value2)

     Here's an example:

           "image/gif; name=\"b980912.gif\"")
          => ("image/gif" (name . "b980912.gif"))

     Parse a `Content-Disposition' header and return a list on the same
     format as the function above.

     Takes two parameters--a list on the format above, and an attribute.
     Returns the value of the attribute.

           '("image/gif" (name . "b980912.gif")) 'name)
          => "b980912.gif"

     Takes a parameter string and returns an encoded version of the
     string.  This is used for parameters in headers like
     `Content-Type' and `Content-Disposition'.

     Return a comment-free version of a header.

           "Gnus/5.070027 (Pterodactyl Gnus v0.27) (Finnish Landrace)")
          => "Gnus/5.070027  "

     Remove linear white space from a header.  Space inside quoted
     strings and comments is preserved.

           "image/gif; name=\"Name with spaces\"")
          => "image/gif;name=\"Name with spaces\""

     Return the last comment in a header.

           "Gnus/5.070027 (Pterodactyl Gnus v0.27) (Finnish Landrace)")
          => "Finnish Landrace"

     Parse an address and return a list containing the mailbox and the
     plaintext name.

           "Hrvoje Niksic <>")
          => ("" . "Hrvoje Niksic")

     Parse a string with list of addresses and return a list of
     elements like the one described above.

           "Hrvoje Niksic <>, Steinar Bang <>")
          => (("" . "Hrvoje Niksic")
               ("" . "Steinar Bang"))

     Parse a date string and return an Emacs time structure.

     Narrow the buffer to the header section of the buffer.  Point is
     placed at the beginning of the narrowed buffer.

     Narrow the buffer to the header under point.  Understands
     continuation headers.

     Fold the header under point.

     Unfold the header under point.

     Return the value of the field under point.

     Encode the non-ASCII words in the region.  For instance, `Na´ve'
     is encoded as `=?iso-8859-1?q?Na=EFve?='.

     Encode the non-ASCII words in the current buffer.  This function is
     meant to be called narrowed to the headers of a message.

     Encode the words that need encoding in a string, and return the

           "This is na´ve, baby")
          => "This is =?iso-8859-1?q?na=EFve,?= baby"

     Decode the encoded words in the region.

     Decode the encoded words in the string and return the result.

           "This is =?iso-8859-1?q?na=EFve,?= baby")
          => "This is na´ve, baby"

   Currently, `mail-parse' is an abstraction over `ietf-drums',
`rfc2047', `rfc2045' and `rfc2231'.  These are documented in the
subsequent sections.

File: emacs-mime,  Node: Basic Functions,  Next: Standards,  Prev: Interface Functions,  Up: Top

4 Basic Functions

This chapter describes the basic, ground-level functions for parsing and
handling.  Covered here is parsing `From' lines, removing comments from
header lines, decoding encoded words, parsing date headers and so on.
High-level functionality is dealt with in the first chapter (*note
Decoding and Viewing::).

* Menu:

* rfc2045::      Encoding `Content-Type' headers.
* rfc2231::      Parsing `Content-Type' headers.
* ietf-drums::   Handling mail headers defined by RFC822bis.
* rfc2047::      En/decoding encoded words in headers.
* time-date::    Functions for parsing dates and manipulating time.
* qp::           Quoted-Printable en/decoding.
* base64::       Base64 en/decoding.
* binhex::       Binhex decoding.
* uudecode::     Uuencode decoding.
* yenc::         Yenc decoding.
* rfc1843::      Decoding HZ-encoded text.
* mailcap::      How parts are displayed is specified by the `.mailcap' file

File: emacs-mime,  Node: rfc2045,  Next: rfc2231,  Up: Basic Functions

4.1 rfc2045

RFC2045 is the "main" MIME document, and as such, one would imagine
that there would be a lot to implement.  But there isn't, since most of
the implementation details are delegated to the subsequent RFCs.

   So `rfc2045.el' has only a single function:

     Takes a parameter and a value and returns a `PARAM=VALUE' string.
     VALUE will be quoted if there are non-safe characters in it.

File: emacs-mime,  Node: rfc2231,  Next: ietf-drums,  Prev: rfc2045,  Up: Basic Functions

4.2 rfc2231

RFC2231 defines a syntax for the `Content-Type' and
`Content-Disposition' headers.  Its snappy name is "MIME Parameter
Value and Encoded Word Extensions: Character Sets, Languages, and

   In short, these headers look something like this:

     Content-Type: application/x-stuff;
      title*2="isn't it!"

   They usually aren't this bad, though.

   The following functions are defined by this library:

     Parse a `Content-Type' header and return a list describing its

           title*2=\"isn't it!\"")
          => ("application/x-stuff"
              (title . "This is even more ***fun*** isn't it!"))

     Takes one of the lists on the format above and returns the value
     of the specified attribute.

     Encode a parameter in headers likes `Content-Type' and

File: emacs-mime,  Node: ietf-drums,  Next: rfc2047,  Prev: rfc2231,  Up: Basic Functions

4.3 ietf-drums

"drums" is an IETF working group that is working on the replacement for

   The functions provided by this library include:

     Remove the comments from the argument and return the results.

     Remove linear white space from the string and return the results.
     Spaces inside quoted strings and comments are left untouched.

     Return the last most comment from the string.

     Parse an address string and return a list that contains the
     mailbox and the plain text name.

     Parse a string that contains any number of comma-separated
     addresses and return a list that contains mailbox/plain text pairs.

     Parse a date string and return an Emacs time structure.

     Narrow the buffer to the header section of the current buffer.

File: emacs-mime,  Node: rfc2047,  Next: time-date,  Prev: ietf-drums,  Up: Basic Functions

4.4 rfc2047

RFC2047 (Message Header Extensions for Non-ASCII Text) specifies how
non-ASCII text in headers are to be encoded.  This is actually rather
complicated, so a number of variables are necessary to tweak what this
library does.

   The following variables are tweakable:

     This is an alist of header / encoding-type pairs.  Its main
     purpose is to prevent encoding of certain headers.

     The keys can either be header regexps, or `t'.

     The values can be `nil', in which case the header(s) in question
     won't be encoded, `mime', which means that they will be encoded, or
     `address-mime', which means the header(s) will be encoded carefully
     assuming they contain addresses.

     RFC2047 specifies two forms of encoding--`Q' (a
     Quoted-Printable-like encoding) and `B' (base64).  This alist
     specifies which charset should use which encoding.

     This is an alist of encoding / function pairs.  The encodings are
     `Q', `B' and `nil'.

     When decoding words, this library looks for matches to this regexp.

     This is a version from which the regexp for the Q encoding pattern
     of `rfc2047-encoded-word-regexp' is made loose.

     The boolean variable specifies whether encoded words (e.g.
     `=?us-ascii?q?hello?=') should be encoded again.
     `rfc2047-encoded-word-regexp' is used to look for such words.

     The boolean variable specifies whether irregular Q encoded words
     (e.g. `=?us-ascii?q?hello??=') should be decoded.  If it is
     non-`nil', `rfc2047-encoded-word-regexp-loose' is used instead of
     `rfc2047-encoded-word-regexp' to look for encoded words.

   Those were the variables, and these are this functions:

     Narrow the buffer to the header on the current line.

     Should be called narrowed to the header of a message.  Encodes
     according to `rfc2047-header-encoding-alist'.

     Encodes all encodable words in the region specified.

     Encode a string and return the results.

     Decode the encoded words in the region.

     Decode a string and return the results.

     Encode a parameter in the RFC2047-like style.  This is a
     replacement for the `rfc2231-encode-string' function.  *Note

     When attaching files as MIME parts, we should use the RFC2231
     encoding to specify the file names containing non-ASCII
     characters.  However, many mail softwares don't support it in
     practice and recipients won't be able to extract files with
     correct names.  Instead, the RFC2047-like encoding is acceptable
     generally.  This function provides the very RFC2047-like encoding,
     resigning to such a regrettable trend.  To use it, put the
     following line in your `~/.gnus.el' file:

          (defalias 'mail-header-encode-parameter 'rfc2047-encode-parameter)

File: emacs-mime,  Node: time-date,  Next: qp,  Prev: rfc2047,  Up: Basic Functions

4.5 time-date

While not really a part of the MIME library, it is convenient to
document this library here.  It deals with parsing `Date' headers and
manipulating time.  (Not by using tesseracts, though, I'm sorry to say.)

   These functions convert between five formats: A date string, an Emacs
time structure, a decoded time list, a second number, and a day number.

   Here's a bunch of time/date/second/day examples:

     (parse-time-string "Sat Sep 12 12:21:54 1998 +0200")
     => (54 21 12 12 9 1998 6 nil 7200)

     (date-to-time "Sat Sep 12 12:21:54 1998 +0200")
     => (13818 19266)

     (time-to-seconds '(13818 19266))
     => 905595714.0

     (seconds-to-time 905595714.0)
     => (13818 19266 0)

     (time-to-days '(13818 19266))
     => 729644

     (days-to-time 729644)
     => (961933 65536)

     (time-since '(13818 19266))
     => (0 430)

     (time-less-p '(13818 19266) '(13818 19145))
     => nil

     (subtract-time '(13818 19266) '(13818 19145))
     => (0 121)

     (days-between "Sat Sep 12 12:21:54 1998 +0200"
                   "Sat Sep 07 12:21:54 1998 +0200")
     => 5

     (date-leap-year-p 2000)
     => t

     (time-to-day-in-year '(13818 19266))
     => 255

       (date-to-time "Mon, 01 Jan 2001 02:22:26 GMT")))
     => 4.146122685185185

   And finally, we have `safe-date-to-time', which does the same as
`date-to-time', but returns a zero time if the date is syntactically

   The five data representations used are the following:

     An RFC822 (or similar) date string.  For instance: `"Sat Sep 12
     12:21:54 1998 +0200"'.

     An internal Emacs time.  For instance: `(13818 26466)'.

     A floating point representation of the internal Emacs time.  For
     instance: `905595714.0'.

     An integer number representing the number of days since 00000101.
     For instance: `729644'.

     A list of decoded time.  For instance: `(54 21 12 12 9 1998 6 t

   All the examples above represent the same moment.

   These are the functions available:

     Take a date and return a time.

     Take a time and return seconds.

     Take seconds and return a time.

     Take a time and return days.

     Take days and return a time.

     Take a date and return days.

     Take a time and return the number of days that represents.

     Take a date and return a time.  If the date is not syntactically
     valid, return a "zero" time.

     Take two times and say whether the first time is less (i. e.,
     earlier) than the second time.

     Take a time and return a time saying how long it was since that

     Take two times and subtract the second from the first.  I. e.,
     return the time between the two times.

     Take two days and return the number of days between those two days.

     Take a year number and say whether it's a leap year.

     Take a time and return the day number within the year that the
     time is in.

File: emacs-mime,  Node: qp,  Next: base64,  Prev: time-date,  Up: Basic Functions

4.6 qp

This library deals with decoding and encoding Quoted-Printable text.

   Very briefly explained, qp encoding means translating all 8-bit
characters (and lots of control characters) into things that look like
`=EF'; that is, an equal sign followed by the byte encoded as a hex

   The following functions are defined by the library:

     QP-decode all the encoded text in the specified region.

     Decode the QP-encoded text in a string and return the results.

     QP-encode all the encodable characters in the specified region.
     The third optional parameter FOLD specifies whether to fold long
     lines.  (Long here means 72.)

     QP-encode all the encodable characters in a string and return the

File: emacs-mime,  Node: base64,  Next: binhex,  Prev: qp,  Up: Basic Functions

4.7 base64

Base64 is an encoding that encodes three bytes into four characters,
thereby increasing the size by about 33%.  The alphabet used for
encoding is very resistant to mangling during transit.

   The following functions are defined by this library:

     base64 encode the selected region.  Return the length of the
     encoded text.  Optional third argument NO-LINE-BREAK means do not
     break long lines into shorter lines.

     base64 encode a string and return the result.

     base64 decode the selected region.  Return the length of the
     decoded text.  If the region can't be decoded, return `nil' and
     don't modify the buffer.

     base64 decode a string and return the result.  If the string can't
     be decoded, `nil' is returned.

File: emacs-mime,  Node: binhex,  Next: uudecode,  Prev: base64,  Up: Basic Functions

4.8 binhex

`binhex' is an encoding that originated in Macintosh environments.  The
following function is supplied to deal with these:

     Decode the encoded text in the region.  If given a third
     parameter, only decode the `binhex' header and return the filename.

File: emacs-mime,  Node: uudecode,  Next: yenc,  Prev: binhex,  Up: Basic Functions

4.9 uudecode

`uuencode' is probably still the most popular encoding of binaries used
on Usenet, although `base64' rules the mail world.

   The following function is supplied by this package:

     Decode the text in the region.

File: emacs-mime,  Node: yenc,  Next: rfc1843,  Prev: uudecode,  Up: Basic Functions

4.10 yenc

`yenc' is used for encoding binaries on Usenet.  The following function
is supplied by this package:

     Decode the encoded text in the region.

File: emacs-mime,  Node: rfc1843,  Next: mailcap,  Prev: yenc,  Up: Basic Functions

4.11 rfc1843

RFC1843 deals with mixing Chinese and ASCII characters in messages.  In
essence, RFC1843 switches between ASCII and Chinese by doing this:

     This sentence is in ASCII.
     The next sentence is in GB.~{<:Ky2;S{#,NpJ)l6HK!#~}Bye.

   Simple enough, and widely used in China.

   The following functions are available to handle this encoding:

     Decode HZ-encoded text in the region.

     Decode a HZ-encoded string and return the result.

File: emacs-mime,  Node: mailcap,  Prev: rfc1843,  Up: Basic Functions

4.12 mailcap

The `~/.mailcap' file is parsed by most MIME-aware message handlers and
describes how elements are supposed to be displayed.  Here's an example

     image/*; gimp -8 %s
     audio/wav; wavplayer %s
     application/msword; catdoc %s ; copiousoutput ; nametemplate=%s.doc

   This says that all image files should be displayed with `gimp', that
WAVE audio files should be played by `wavplayer', and that MS-WORD
files should be inlined by `catdoc'.

   The `mailcap' library parses this file, and provides functions for
matching types.

     This variable is an alist of alists containing backup viewing

   Interface functions:

     Parse the `~/.mailcap' file.

     Takes a MIME type as its argument and returns the matching viewer.

File: emacs-mime,  Node: Standards,  Next: GNU Free Documentation License,  Prev: Basic Functions,  Up: Top

5 Standards

The Emacs MIME library implements handling of various elements
according to a (somewhat) large number of RFCs, drafts and standards
documents.  This chapter lists the relevant ones.  They can all be
fetched from `'.

     Standard for the Format of ARPA Internet Text Messages.

     Standard for Interchange of USENET Messages

     Format of Internet Message Bodies

     Media Types

     Message Header Extensions for Non-ASCII Text

     Registration Procedures

     Conformance Criteria and Examples

     MIME Parameter Value and Encoded Word Extensions: Character Sets,
     Languages, and Continuations

     HZ - A Data Format for Exchanging Files of Arbitrarily Mixed
     Chinese and ASCII characters

     Draft for the successor of RFC822

     The MIME Multipart/Related Content-type

     The Multipart/Report Content Type for the Reporting of Mail System
     Administrative Messages

     Communicating Presentation Information in Internet Messages: The
     Content-Disposition Header Field

     Documentation of the text/plain format parameter for flowed text.

File: emacs-mime,  Node: GNU Free Documentation License,  Next: Index,  Prev: Standards,  Up: Top

6 GNU Free Documentation License

                     Version 1.3, 3 November 2008

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File: emacs-mime,  Node: Index,  Prev: GNU Free Documentation License,  Up: Top

7 Index

* Menu:

* Apple:                                 binhex.              (line   6)
* base64:                                base64.              (line   6)
* base64-decode-region:                  base64.              (line  21)
* base64-decode-string:                  base64.              (line  26)
* base64-encode-region:                  base64.              (line  13)
* base64-encode-string:                  base64.              (line  18)
* binhex <1>:                            binhex.              (line   6)
* binhex:                                Non-MIME.            (line  21)
* binhex-decode-region:                  binhex.              (line  10)
* charsets:                              Charset Translation. (line   6)
* Chinese:                               rfc1843.             (line   6)
* Composing:                             Composing.           (line   6)
* diff:                                  Non-MIME.            (line  49)
* emacs-sources:                         Non-MIME.            (line  45)
* format=flowed:                         Flowed text.         (line   6)
* forward:                               Non-MIME.            (line  30)
* gnatsweb:                              Non-MIME.            (line  33)
* HZ:                                    rfc1843.             (line   6)
* ietf-drums-get-comment:                ietf-drums.          (line  19)
* ietf-drums-narrow-to-header:           ietf-drums.          (line  33)
* ietf-drums-parse-address:              ietf-drums.          (line  22)
* ietf-drums-parse-addresses:            ietf-drums.          (line  26)
* ietf-drums-parse-date:                 ietf-drums.          (line  30)
* ietf-drums-remove-comments:            ietf-drums.          (line  12)
* ietf-drums-remove-whitespace:          ietf-drums.          (line  15)
* interface functions:                   Interface Functions. (line   6)
* LaTeX:                                 Non-MIME.            (line  57)
* Macintosh:                             binhex.              (line   6)
* mail-content-type-get:                 Interface Functions. (line  54)
* mail-decode-encoded-word-region:       Interface Functions. (line 142)
* mail-decode-encoded-word-string:       Interface Functions. (line 145)
* mail-encode-encoded-word-buffer:       Interface Functions. (line 130)
* mail-encode-encoded-word-region:       Interface Functions. (line 126)
* mail-encode-encoded-word-string:       Interface Functions. (line 134)
* mail-header-encode-parameter:          Interface Functions. (line  62)
* mail-header-field-value:               Interface Functions. (line 123)
* mail-header-fold-field:                Interface Functions. (line 117)
* mail-header-get-comment:               Interface Functions. (line  82)
* mail-header-narrow-to-field:           Interface Functions. (line 113)
* mail-header-parse-address:             Interface Functions. (line  89)
* mail-header-parse-addresses:           Interface Functions. (line  97)
* mail-header-parse-content-disposition: Interface Functions. (line  50)
* mail-header-parse-content-type:        Interface Functions. (line  35)
* mail-header-parse-date:                Interface Functions. (line 106)
* mail-header-remove-comments:           Interface Functions. (line  67)
* mail-header-remove-whitespace:         Interface Functions. (line  74)
* mail-header-unfold-field:              Interface Functions. (line 120)
* mail-narrow-to-head:                   Interface Functions. (line 109)
* mail-parse:                            Interface Functions. (line   6)
* mail-parse-charset:                    Charset Translation. (line   9)
* mailcap-mime-data:                     mailcap.             (line  22)
* mailcap-parse-mailcaps:                mailcap.             (line  29)
* MIME Composing:                        Composing.           (line   6)
* MIME Meta Language:                    Composing.           (line   6)
* mime-to-mml:                           Conversion.          (line   6)
* mm-attachment-override-types:          Display Customization.
                                                              (line  35)
* mm-automatic-display:                  Display Customization.
                                                              (line  22)
* mm-automatic-display-p:                Display.             (line  18)
* mm-automatic-external-display:         Display Customization.
                                                              (line  27)
* mm-body-charset-encoding-alist:        Encoding Customization.
                                                              (line   7)
* mm-coding-system-priorities:           Encoding Customization.
                                                              (line  24)
* mm-content-transfer-encoding-defaults: Encoding Customization.
                                                              (line  63)
* mm-default-directory:                  Files and Directories.
                                                              (line   7)
* mm-destroy-part:                       Display.             (line  21)
* mm-discouraged-alternatives:           Display Customization.
                                                              (line  42)
* mm-display-part:                       Display.             (line   9)
* mm-enable-external:                    Display Customization.
                                                              (line 126)
* mm-external-terminal-program:          Display Customization.
                                                              (line 123)
* mm-file-name-collapse-whitespace:      Files and Directories.
                                                              (line  33)
* mm-file-name-delete-control:           Files and Directories.
                                                              (line  19)
* mm-file-name-delete-gotchas:           Files and Directories.
                                                              (line  22)
* mm-file-name-delete-whitespace:        Files and Directories.
                                                              (line  27)
* mm-file-name-replace-whitespace:       Files and Directories.
                                                              (line  36)
* mm-file-name-rewrite-functions:        Files and Directories.
                                                              (line  14)
* mm-file-name-trim-whitespace:          Files and Directories.
                                                              (line  30)
* mm-fill-flowed:                        Flowed text.         (line  25)
* mm-handle-buffer:                      Handles.             (line  11)
* mm-handle-disposition:                 Handles.             (line  28)
* mm-handle-encoding:                    Handles.             (line  18)
* mm-handle-set-undisplayer:             Handles.             (line  25)
* mm-handle-type:                        Handles.             (line  15)
* mm-handle-undisplayer:                 Handles.             (line  21)
* mm-inlinable-p:                        Display.             (line  15)
* mm-inline-large-images:                Display Customization.
                                                              (line  77)
* mm-inline-media-tests:                 Display Customization.
                                                              (line   7)
* mm-inline-override-types:              Display Customization.
                                                              (line  87)
* mm-inline-text-html-with-images:       Display Customization.
                                                              (line 104)
* mm-inline-text-html-with-w3m-keymap:   Display Customization.
                                                              (line 119)
* mm-inlined-types:                      Display Customization.
                                                              (line  17)
* mm-interactively-view-part:            Display.             (line  30)
* mm-keep-viewer-alive-types:            Display Customization.
                                                              (line  31)
* mm-mime-mule-charset-alist:            Charset Translation. (line  18)
* mm-path-name-rewrite-functions:        Files and Directories.
                                                              (line  44)
* mm-pipe-part:                          Display.             (line  27)
* mm-remove-part:                        Display.             (line  12)
* mm-save-part:                          Display.             (line  24)
* mm-text-html-renderer:                 Display Customization.
                                                              (line  97)
* mm-tmp-directory:                      Files and Directories.
                                                              (line  11)
* mm-use-ultra-safe-encoding:            Encoding Customization.
                                                              (line  82)
* mm-uu-configure-list:                  Non-MIME.            (line   6)
* mm-uu-diff-groups-regexp:              Non-MIME.            (line  49)
* mm-uu-emacs-sources-regexp:            Non-MIME.            (line  45)
* mm-uu-extract:                         Non-MIME.            (line  61)
* mm-w3m-safe-url-regexp:                Display Customization.
                                                              (line 113)
* MML:                                   Composing.           (line   6)
* mml-generate-mime:                     Composing.           (line  10)
* mml-to-mime:                           Conversion.          (line  12)
* MULE:                                  Charset Translation. (line  18)
* pgp-encrypted:                         Non-MIME.            (line  39)
* pgp-key:                               Non-MIME.            (line  42)
* pgp-signed:                            Non-MIME.            (line  36)
* postscript:                            Non-MIME.            (line  15)
* quoted-printable-decode-region:        qp.                  (line  16)
* quoted-printable-decode-string:        qp.                  (line  19)
* quoted-printable-encode-region:        qp.                  (line  22)
* quoted-printable-encode-string:        qp.                  (line  27)
* rfc1843:                               rfc1843.             (line   6)
* rfc2045-encode-string:                 rfc2045.             (line  13)
* rfc2047-allow-irregular-q-encoded-words: rfc2047.           (line  46)
* rfc2047-charset-encoding-alist:        rfc2047.             (line  25)
* rfc2047-decode-region:                 rfc2047.             (line  68)
* rfc2047-decode-string:                 rfc2047.             (line  71)
* rfc2047-encode-encoded-words:          rfc2047.             (line  41)
* rfc2047-encode-function-alist:         rfc2047.             (line  30)
* rfc2047-encode-message-header:         rfc2047.             (line  58)
* rfc2047-encode-parameter:              rfc2047.             (line  74)
* rfc2047-encode-region:                 rfc2047.             (line  62)
* rfc2047-encode-string:                 rfc2047.             (line  65)
* rfc2047-encoded-word-regexp:           rfc2047.             (line  34)
* rfc2047-encoded-word-regexp-loose:     rfc2047.             (line  37)
* rfc2047-header-encoding-alist:         rfc2047.             (line  14)
* rfc2047-narrow-to-field:               rfc2047.             (line  55)
* rfc2231-encode-string:                 rfc2231.             (line  39)
* rfc2231-get-value:                     rfc2231.             (line  35)
* rfc2231-parse-string:                  rfc2231.             (line  23)
* shar:                                  Non-MIME.            (line  27)
* text/x-verbatim:                       Non-MIME.            (line  61)
* Unicode:                               Charset Translation. (line  18)
* UTF-8:                                 Charset Translation. (line  18)
* uu:                                    Non-MIME.            (line  18)
* uudecode:                              uudecode.            (line   6)
* uudecode-decode-region:                uudecode.            (line  12)
* uuencode:                              uudecode.            (line   6)
* verbatim-marks:                        Non-MIME.            (line  54)
* yenc <1>:                              yenc.                (line   6)
* yenc:                                  Non-MIME.            (line  24)
* yenc-decode-region:                    yenc.                (line  10)