MIME
(Multipurpose Internet Mail Extensions)
Part One:

Mechanisms for Specifying and Describing
the Format of Internet Message Bodies

Status of this Memo

This RFC 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" for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Table of Contents

• Abstract
• 1. Introduction
• 2. Notations, Conventions, and Generic BNF Grammar
• 3. The MIME-Version Header Field
• 4. The Content-Type Header Field
• 5. The Content-Transfer-Encoding Header Field
  • 5.1. Quoted-Printable Content-Transfer-Encoding
  • 5.2. Base64 Content-Transfer-Encoding
• 6. Additional Content-Header Fields
  • 6.1. Optional Content-ID Header Field
  • 6.2. Optional Content-Description Header Field
• 7. The Predefined Content-Type Values
  • 7.1 The Text Content-Type
    • 7.1.1. The charset parameter
    • 7.1.2. The Text/plain subtype
  • 7.2. The Multipart Content-Type
    • 7.2.1. Multipart: The common syntax
    • 7.2.2. The Multipart/mixed (primary) subtype
    • 7.2.3. The Multipart/alternative subtype
    • 7.2.4. The Multipart/digest subtype
    • 7.2.5. The Multipart/parallel subtype
    • 7.2.6. Other Multipart subtypes
  • 7.3. The Message Content-Type
    • 7.3.1. The Message/rfc822 (primary) subtype
    • 7.3.2. The Message/Partial subtype
    • 7.3.3. The Message/External-Body subtype
  • 7.4. The Application Content-Type
    • 7.4.1. The Application/Octet-Stream (primary) subtype
    • 7.4.2. The Application/PostScript subtype
    • 7.4.3. Other Application subtypes
  • 7.5. The Image Content-Type
  • 7.6. The Audio Content-Type
  • 7.7. The Video Content-Type
  • 7.8. Experimental Content-Type Values
• 8. Summary
• 9. Security Considerations
• 10. Authors' Addresses
  • Nathaniel S. Borenstein
  • Ned Freed
  • Gregory M. Vaudreuil
• 11. Acknowledgements
• Appendix A -- Minimal MIME-Conformance
• Appendix B -- General Guidelines For Sending Email Data
• Appendix C -- A Complex Multipart Example
• Appendix D -- Collected Grammar
• Appendix E -- IANA Registration Procedures
  • E.1 Registration of New Content-type/subtype Values
  • E.2 Registration of New Access-type Values for Message/external-body
• Appendix F -- Summary of the Seven Content-types
• Appendix G -- Canonical Encoding Model
• Appendix H -- Changes from RFC 1341
• References