Important Parameters: charset

   Encoding notes: quoted-printable generally preferred if an encoding
      is needed and the character set is mostly an ASCII superset.

   Security considerations: Rich text formats such as TeX and Troff
      often contain mechanisms for executing arbitrary commands or file
      system operations, and should not be used automatically unless
      these security problems have been addressed.  Even plain text may
      contain control characters that can be used to exploit the
      capabilities of "intelligent" terminals and cause security
      violations.  User interfaces designed to run on such terminals
      should be aware of and try to prevent such problems.

   ________________________________________________________
   Content-type: multipart

   Subtypes defined by  this  document: mixed, alternative,
        digest, parallel.

   Important Parameters: boundary

   Encoding notes: No content-transfer-encoding is permitted.

   ________________________________________________________
   Content-type: message

   Subtypes defined by this document: rfc822, partial, external-body

   Important Parameters: id, number, total, access-type, expiration,
      size, permission, name, site, directory, mode, server, subject

   Encoding notes: No content-transfer-encoding is permitted.
      Specifically, only "7bit" is permitted for "message/partial" or
      "message/external-body", and only "7bit", "8bit", or "binary" are
      permitted for other subtypes of "message".
   ______________________________________________________________
   Content-type: application

   Subtypes defined by this document:  octet-stream, postscript

   Important Parameters:  type, padding




 
RFC 1521                          MIME                    September 1993


   Deprecated Parameters: name and conversions were
                          defined in RFC 1341.

   Encoding notes: base64 preferred for unreadable subtypes.

   Security considerations:  This  type  is  intended  for  the
   transmission  of data to be interpreted by locally-installed
   programs.  If used,  for  example,  to  transmit  executable
   binary  programs  or programs in general-purpose interpreted
   languages, such as LISP programs or  shell  scripts,  severe
   security  problems  could  result.   Authors of mail-reading
   agents are cautioned against giving their systems the  power
   to  execute  mail-based  application  data without carefully
   considering  the  security  implications.    While   it   is
   certainly  possible  to  define safe application formats and
   even safe interpreters for unsafe formats, each  interpreter
   should   be   evaluated  separately  for  possible  security
   problems.
   ________________________________________________________________
   Content-type: image

   Subtypes defined by this document:  jpeg, gif

   Important Parameters: none

   Encoding notes: base64 generally preferred
   ________________________________________________________________
   Content-type: audio

   Subtypes defined by this document:  basic

   Important Parameters: none

   Encoding notes: base64 generally preferred
   ________________________________________________________________
   Content-type: video

   Subtypes defined by this document:  mpeg

   Important Parameters: none

   Encoding notes: base64 generally preferred