MIME Encapsulation of Macintosh Files - MacMIME (RFC1740)
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
P. Faltstrom: AUTHOR [+3]
This memo describes the format to use when sending Apple Macintosh files via MIME [BORE93]. The format is compatible with existing mechanisms for distributing Macintosh files, while allowing non- Macintosh systems access to data in standardized formats.
Network Working Group Patrik Faltstrom
Request for Comments: 1740 Royal Institute of Technology
Category: Standards Track Dave Crocker
Erik E. Fair
Apple Computer Inc.
MIME Encapsulation of Macintosh files - MacMIME
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
This memo describes the format to use when sending Apple Macintosh
files via MIME [BORE93]. The format is compatible with existing
mechanisms for distributing Macintosh files, while allowing non-
Macintosh systems access to data in standardized formats.
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 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.
The two styles of use are [APPL90]:
AppleSingle: Apple's standard format for encoding Macintosh files
as one byte stream.
AppleDouble: Similar to AppleSingle except that the Data fork is
separated from the Macintosh-specific parts by the
AppleDouble 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) as it is separated
from the AppleDouble encoding.
2. MIME format for Apple/Macintosh-specific file information