RFC 1740 (rfc1740) - Page 2 of 16
MIME Encapsulation of Macintosh Files - MacMIME
Alternative Format: Original Text Document
RFC 1740 MIME-based Mac files December 1994
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 encoding.
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
2a. APPLICATION/APPLEFILE
MIME type-name: APPLICATION
MIME subtype name: APPLEFILE
Required parameters: none
Optional parameters: NAME, which must be a "value" as
defined in RFC-1521 [BORE93].
Encoding considerations: The presence of binary data will
typically require use of
Content-Transfer-Encoding: BASE64
Security considerations: See separate section in the document
Published specification: Apple-single & Apple-double [APPL90]
Rationale: Permits MIME-based transmission of
data with Apple/Macintosh specific
information, while allowing general
access to non-specific user data.
2b. MULTIPART/APPLEDOUBLE
MIME type-name: MULTIPART
MIME subtype name: APPLEDOUBLE
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: Apple-single & Apple-double [APPL90]
Rationale: Permits MIME-based transmission of
data with Apple/Macintosh specific
information, while allowing general
access to non-specific user data.
Faltstrom, Crocker & Fair