Media Type Specifications and Registration Procedures
RFC 4288

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 05

Network Working Group                                           N. Freed
Request for Comments: 4288                              Sun Microsystems
BCP: 13                                                       J. Klensin
Obsoletes: 2048                                            December 2005
Category: Best Current Practice

         Media Type Specifications and Registration Procedures

Status of This Memo

   This document specifies an Internet Best Current Practices for the
   Internet Community, and requests discussion and suggestions for
   improvements.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This document defines procedures for the specification and
   registration of media types for use in MIME and other Internet
   protocols.

Freed & Klensin          Best Current Practice                  [Page 1]
RFC 4288                Media Type Registration            December 2005

Table of Contents

   1. Introduction ....................................................3
   2. Media Type Registration Preliminaries ...........................4
   3. Registration Trees and Subtype Names ............................4
      3.1. Standards Tree .............................................4
      3.2. Vendor Tree ................................................5
      3.3. Personal or Vanity Tree ....................................5
      3.4. Special x. Tree ............................................5
      3.5. Additional Registration Trees ..............................6
   4. Registration Requirements .......................................6
      4.1. Functionality Requirement ..................................6
      4.2. Naming Requirements ........................................6
         4.2.1. Text Media Types ......................................7
         4.2.2. Image Media Types .....................................8
         4.2.3. Audio Media Types .....................................8
         4.2.4. Video Media Types .....................................8
         4.2.5. Application Media Types ...............................9
         4.2.6. Multipart and Message Media Types .....................9
         4.2.7. Additional Top-level Types ............................9
      4.3. Parameter Requirements ....................................10
      4.4. Canonicalization and Format Requirements ..................10
      4.5. Interchange Recommendations ...............................11
      4.6. Security Requirements .....................................11
      4.7. Requirements specific to XML media types ..................13
      4.8. Encoding Requirements .....................................13
      4.9. Usage and Implementation Non-requirements .................13
      4.10. Publication Requirements .................................14
      4.11. Additional Information ...................................15
   5. Registration Procedure .........................................15
      5.1. Preliminary Community Review ..............................16
      5.2. IESG Approval .............................................16
      5.3. IANA Registration .........................................16
      5.4. Media Types Reviewer ......................................16
   6. Comments on Media Type Registrations ...........................17
   7. Location of Registered Media Type List .........................17
   8. IANA Procedures for Registering Media Types ....................17
   9. Change Procedures ..............................................18
   10. Registration Template .........................................19
   11. Security Considerations .......................................20
   12. IANA Considerations ...........................................20
   13. Acknowledgements ..............................................20
   14. References ....................................................20
   Appendix A.  Grandfathered Media Types ............................22
   Appendix B.  Changes Since RFC 2048 ...............................22

Freed & Klensin          Best Current Practice                  [Page 2]
RFC 4288                Media Type Registration            December 2005

1.  Introduction

   Recent Internet protocols have been carefully designed to be easily
   extensible in certain areas.  In particular, many protocols,
   including but not limited to MIME [RFC2045], are capable of carrying
   arbitrary labeled content.  A mechanism is needed to label such
   content and a registration process is needed for these labels, to
   ensure that the set of such values is developed in an orderly, well-
   specified, and public manner.

   This document defines media type specification and registration
   procedures that use the Internet Assigned Numbers Authority (IANA) as
   a central registry.

   Historical Note

      The media type registration process was initially defined for