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Registration of Charset and Languages Media Features Tags (RFC2987) Disclosure Number: IPCOM000005180D
Original Publication Date: 2000-Nov-01
Included in the Prior Art Database: 2019-Feb-12
Document File: 6 page(s) / 7K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

P. Hoffman: AUTHOR

Related Documents

10.17487/RFC2987: DOI


This document contains the registration for two media feature tags: "charset" and "language". [STANDARDS-TRACK]

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 39% of the total text.

Network Working Group P. Hoffman Request for Comments: 2987 Internet Mail Consortium Category: Standards Track November 2000

Registration of Charset and Languages Media Features Tags

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

Copyright (C) The Internet Society (2000). All Rights Reserved.


This document contains the registration for two media feature tags: "charset" and "language". These media features allow specification of character sets and human languages that can be understood by devices and the devices’ users. The templates in this document are derived from RFC 2506.

1. Registration for charset

To: (Media feature tags mailing list) Subject: Registration of media feature tag charset

Media feature tag name: charset

ASN.1 identifier associated with feature tag:

Summary of the media feature indicated by this feature tag: Ability to display particular charsets as defined in [CHARSET]. For most devices, this media feature is usually a capability; that is, most devices cannot intelligently process text in a charset that is unknown to the device.

Hoffman Standards Track [Page 1]

RFC 2987 Charset and Languages Media Features Tags November 2000

Values appropriate for use with this feature tag: The values are tokens as defined in [CHARSET]. The values can only be compared for equality. Comparison is not case sensitive.

The feature tag is intended primarily for use in the following applications, protocols, services, or negotiation mechanisms: Any protocol that uses media tags

Examples of typical use: (| (charset=utf-8);q=1.0 (charset=iso-8859-1);q=0.9 (charset=utf-16);q=0.5 )

Related standards or documents: "IANA Charset Registration Procedures", RFC 2978

Considerations particular to use in individual applications, protocols, services, or negotiation mechanisms: None

Interoperability considerations: Aliases for charsets should not be used in media feature expressions because feature expression manipulation tools may convert aliases to the the principal name for the charset. Even though charset names are not case-sensitive, values should be expressed as all lowercase letters to increase the likelihood of interoperability. The "charset" capability should always be indicated in conjunction with any capability to handle textual data.

Security considerations: If it is known that there is a security bug in the display of a particular charset in a particular environment, knowing that a device can accept that charset may slightly help an attacker.

Additional information: None

Name(s) & email address(es) of person(s) to contact for further information: Paul Hoffman <phoffman@imc...