MIME Multipurpose Internet Mail Extensions

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MIME (Multipurpose Internet Mail Extensions)

• RFC 2045 General Structure of MIME messages
• RFC 2046 Defines the general structure of the
  MIME media typing system and an initial set of
  media types
• RFC 2047 Message header extensions for non-ASCII
  text
• RFC 2048 IANA registration procedures for
  MIME-related facilities

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MIME (Multipurpose Internet Mail Extensions)

• Encoded-word
• encoded-word ? charset ? encoding ?
  encoded-text ?
• charset token
• US-ASCII ISO-8859-
• encoding token
• B - BASE64, Q - Quoted-Printable
• encoded-text.
• For Q encoding, any 8-bit value XY, X Y
  are hexadecimal digits
• Examples
• ?iso-8859-1?Q?RE_C7EBBDCC?
• ?iso-8859-1?q?this20is20some20text?

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MIME (Multipurpose Internet Mail Extensions)

• An encoded-word may not more than 75 characters
  long
• Multiple encoded-words may be used in separated
  lines
• No space is allowed in encoded-word
• No recursive encoding allowed
• Encoded-words may not appear in some header
  fields
• Received Header MIME Content Type

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MIME (Multipurpose Internet Mail Extensions)

• Content-Type header media type / subtype
• Media type (initial seven standard top-level
  media)
• text textual information
• image image data
• audio audio data
• video video data
• application some other data
• multipart data consisting of multiple entities
  of independent data types
• message an encapsulated message

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MIME (Multipurpose Internet Mail Extensions)

• IETF Tree
• Vendor Tree
• Personal or Vanity Tree
• Special x. Tree
• Additional Registration Tree

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MIME (Multipurpose Internet Mail Extensions)

• Registration Requirement
• Functionality Requirements must function as an
  actual media format
• Naming Requirements all registered media types
  must be assigned MIME type and subtype names
• Parameter Requirements
• Canonicalization and Format Requirements
• Interchange Recommendations
• Security Requirements
• Publication Requirements

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MIME (Multipurpose Internet Mail Extensions)

• Registration Procedure
• Present the media type to the community for
  review
• ietf-types_at_iana.org
• IESG approval
• IANA Registration