RFC 1741 (rfc1741) - Page 2 of 6

MIME Content Type for BinHex Encoded Files

RFC 1741             Content Type for BinHex Files         December 1994


   AppleDouble file format [APPL90], encoded in MIME as
   multipart/appledouble [FALT94] and application/applefile [FALT94] is
   the preferred format for a Macintosh file that is to be included in
   an Internet mail message, because it provides recipients with
   Macintosh computers the entire document, including Icons and other
   Macintosh specific information, while other users easily can extract
   the Data fork (the actual data).

   However, this specification provides for use of the currently popular
   BinHex4.0 encoding schemes, as a convinience to the installed base of
   users.

2.  MIME format for BinHex4.0

   MIME-base Apple information is specified by:

   MIME type-name:            APPLICATION
   MIME subtype name:         MAC-BINHEX40
   Required parameters:       none
   Optional parameters:       NAME, which must be a "value" as
                              defined in RFC-1521 [BORE93].
   Encoding considerations:   none
   Security considerations:   See separate section in the document
   Published specification:   Appendix A
   Rationale:                 Permits MIME-based transmission of data
                              with Apple Macintosh file system specific
                              information using a currently popular,
                              though platform specific, format.

   2a.  Detail specific to MIME-based usage

      Macintosh documents do not always need to be sent in a special
      format.  Those documents with well-known MIME types and non-
      existent or trivial resource forks can be sent as regular MIME
      body parts, without use of AppleSingle, AppleDouble or BinHex4.0.

      Documents which lack a data fork must be sent as AppleSingle
      according to RFC 1740 [FALT94].

      Unless there are strong reasons not to, all other documents should
      be sent as AppleDouble according to RFC 1740 [FALT94].  This
      includes documents with non-trivial resource forks, and documents
      without corresponding well-known MIME types.

      It may be valuable in some cases to allow the user to choose one
      format over another, either because he disagrees with the
      implementor's definition of "trivial" resource forks, or for
      reasons of his own.



Faltstrom, Crocker & Fair