MIME Content Type for BinHex Encoded Files
RFC 1741
| Document | Type |
RFC - Informational
(December 1994; No errata)
Was draft-faltstrom-macmime2 (individual)
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|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | Legacy | ||
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| Consensus Boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | RFC 1741 (Informational) | |
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Network Working Group P. Faltstrom
Request for Comments: 1741 Royal Institute of Technology
Category: Informational D. Crocker
Brandenburg Consulting
E. Fair
Apple Computer Inc.
December 1994
MIME Content Type for BinHex Encoded Files
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
This memo describes the format to use when sending BinHex4.0 files
via MIME [BORE93]. The format is compatible with existing mechanisms
for distributing Macintosh files. Only when available software
and/or user practice dictates, should this method be employed. It is
recommended to use application/applefile [FALT94] for maximum
interoperability.
1. Introduction
Files on the Macintosh consists of two parts, called forks:
DATA FORK: The actual data included in the file. The Data
fork is typically the only meaningful part of a
Macintosh file on a non-Macintosh computer system.
For example, if a Macintosh user wants to send a
file of data to a user on an IBM-PC, she would only
send the Data fork.
RESOURCE FORK: Contains a collection of arbitrary attribute/value
pairs, including program segments, icon bitmaps,
and parametric values.
Additional information regarding Macintosh files is stored by the
Finder has in a hidden file, called the "Desktop Database".
Because of the complications in storing different parts of a
Macintosh file in a non-Macintosh filesystem that only handles
consecutive data in one part, it is common to convert the Macintosh
file into some other format before transferring it over the network.
Faltstrom, Crocker & Fair [Page 1]
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 [Page 2]
RFC 1741 Content Type for BinHex Files December 1994
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