Internet Draft                                 Paul Hoffman
draft-hoffman-char-lang-media-02.txt           Internet Mail Consortium
February 15, 2000
Expires in six months

     Registration of Charset and Languages Media Features Tags

Status of this memo

This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.

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Abstract

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
[TAG-REG].

1. Registration for charset

To: media-feature-tags@apps.ietf.org (Media feature tags mailing list)
Subject: Registration of media feature tag charset

Media feature tag name:
    charset

ASN.1 identifier associated with feature tag:
    New assignment by IANA

Summary of the media feature indicated by this feature tag:
    Ability to display particular charsets as defined in [CHARSET]

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 2278

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

Interoperability considerations: 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.org>

Intended usage:
    COMMON

Author/Change controller:
    IETF

Requested IANA publication delay:
    None

Other information:
    None

2. Registration for language

To: media-feature-tags@apps.ietf.org (Media feature tags mailing list)
Subject: Registration of media feature tag language

Media feature tag name:
    language

ASN.1 identifier associated with feature tag:
    New assignment by IANA

Summary of the media feature indicated by this feature tag:
    Ability to display particular human languages as defined in [LANG].
    Note that "display" in this case will most often mean speech
    by a computer.

Values appropriate for use with this feature tag:
    The values are tokens, with allowable values defined by
        registration as defined in [LANG]. The values can only be compared
        for equality. As described in [LANG], language tags are always
        handled as a single token, and "subtags" are not used for
        comparison. 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:
    (| (language=no-nynorsk);q=1.0 (language=no-bokmaal);q=0.9
       (language=i-sami-no);q=0.5 )

Related standards or documents:
    "Tags for the Identification of Languages", RFC 1766

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

Interoperability considerations:
    Even though langage tags are not case-sensitive, values should be
        expressed as all lowercase letters to increase the likelihood of
        interoperability.

Security considerations:
    If it is known that there is a security bug in the display
    of a particular language in a particular environment, knowing
    that a device can accept that language 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.org>

Intended usage:
    COMMON

Author/Change controller:
    IETF

Requested IANA publication delay:
    None

Other information:
    None

3. Security Considerations

The security considerations are listed in the two registrations above.

4. IANA Considerations

The bulk of this document is IANA registrations.

5. References

[CHARSET] "IANA Charset Registration Procedures", RFC 2278

[LANG] "Tags for the Identification of Languages", RFC 1766

[TAG-REG] "Media Feature Tag Registration Procedure", RFC 2506

6. Author Contact Information

Paul Hoffman
Internet Mail Consortium
127 Segre Place
Santa Cruz, CA  95060 USA
phoffman@imc.org