Network Working Group
Request for Comments: 4735
Category: Standards Track

T. Taylor
Nortel
October 2006

Example Media Types for Use in Documentation

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.

Copyright Notice

Abstract

   This document is registration for the 'example' media type and
   'example' subtypes within the standards tree.  The 'example/*' and
   '*/example' media types are defined for documentation purposes only.

1. Introduction

From time to time, documents created by the IETF or by other standards bodies show examples involving the use of media types, where the actual media type is not relevant. It would be useful in such cases to be able to show a media type whose illustrative role in the example is clear. In the worst case, this can be useful to debug implementations where the designer mistook the example for a requirement of the protocol concerned.

To meet this need, this document registers the following media types:

the 'example' media type;

   o  the 'application/example', 'audio/example', 'image/example',
      'message/example', 'model/example', 'multipart/example',
      'text/example', and 'video/example' media subtypes.

It is suggested that compilers of illustrative examples involving media types in trees other than the standards tree might also incorporate the string "example" into their hypothetical media types.

2. Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

3. Registration of the 'example' Media Type

This section registers the 'example' media type in accordance with the requirements of RFC 4288.

Type name: example.

Subtype name: any subtype may be used with the 'example' type. However, IANA MUST NOT register any subtypes for the 'example' media type.

Required parameters: as invented by the user.

Optional parameters: as invented by the user.

Encoding considerations: as invented by the user.

Security considerations: The 'example' media type is defined for use in documentation only. It MUST NOT be implemented. Its appearance in real code could lead to unpredictable results and therefore open up security holes.

Interoperability considerations: Any attempt to negotiate or send the 'example' media type is bound to lead to interoperability problems.

Published specification: this document.

Applications that use this media type: as invented by the user.

Additional information:

      Magic number(s): not applicable.
      File extension(s): not applicable.
      Macintosh file type code(s): not applicable.

Person & email address to contact for further information: ietf-types@iana.org.

Intended usage: LIMITED USE.

Restrictions on usage: This type is intended only for use in documents providing examples involving specification of some media type, where the actual media type used is irrelevant.

Author:

Internet Engineering Task Force

Change controller: Internet Engineering Task Force

4.  Registration of the 'application/example', 'audio/example',

    'image/example', 'message/example', 'model/example',
    'multipart/example', 'text/example', and 'video/example' Subtypes

This section registers 'example' media subtypes in accordance with the requirements of RFC 4288.

    Type name: 'application', 'audio', 'image', 'message', 'model',
    'multipart', 'text', and 'video'.

Subtype name: 'example'.

Required parameters: those required by the type and any others as invented by the user.

Optional parameters: those offered by the type and any others as invented by the user.

Encoding considerations: as invented by the user.

Security considerations: The 'example' media subtypes are defined for use in documentation only. They MUST NOT be implemented. Their appearance in real code could lead to unpredictable results and therefore open up security holes.

Interoperability considerations: Any attempt to negotiate or send one of these 'example' media subtypes is bound to lead to interoperability problems.

Published specification: this document.

Applications that use this media type: as invented by the user.

Additional information:

      Magic number(s): not applicable.
      File extension(s): not applicable.
      Macintosh file type code(s): not applicable.

Person & email address to contact for further information: ietf-types@iana.org.

Intended usage: LIMITED USE.

Restrictions on usage: These subtypes are intended only for use in documents providing examples involving specification of some subtype of the given media type, where the actual subtype used is irrelevant.

Author:

Internet Engineering Task Force

Change controller: Internet Engineering Task Force

5. Security Considerations

The 'example' media type and subtypes are defined for use in documentation only. They MUST NOT be implemented. Any attempt to implement them in real code could lead to unpredictable results and thus potentially open up security holes.

6. IANA Considerations

   This document specifies and registers the 'example' media type and
   the 'application/example', 'audio/example', 'image/example',
   'message/example', 'model/example', 'multipart/example',
   'text/example', and 'video/example' subtypes.

7. Acknowledgements

This document sprang from Magnus Westerland's expression of need and Rod Walsh's support and suggestions for generalization. Warnings against implementation in the Security Considerations and Interoperability Considerations sections and the 'multipart/example' subtype were added at John Klensin's suggestion. Some editing touchups and strengthening of the language in the Security Considerations section were done in response to the Gen-ART reviewer, Sharon Chisholm.

8. Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.
   
   [RFC4288]  Freed, N. and J. Klensin, "Media Type Specifications and
              Registration Procedures", BCP 13, RFC 4288, December 2005.

Author's Address

Tom Taylor
Nortel
1852 Lorraine Ave
Ottawa, Ontario K1H 6Z8
Canada

EMail:

          taylor@nortel.com

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