charset
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... Charset ...
... unconditional and unambiguous conversion in the other
direction is not required, in that not all characters may be
representable by a given charset and a charset may provide more than
one sequence of octets to represent a particular sequence of
...
... direction is not required, in that not all characters may be
representable by a given charset and a charset may provide more than
one sequence of octets to represent a particular sequence of
characters.
...
...
This definition is intended to allow charsets to be defined in a
variety of different ways, from simple single-table mappings such as
US-ASCII ...
... ISO 2022's techniques. However, the definition associated with a
charset name must fully specify the mapping to be performed. In
particular, use of external profiling information to determine the
exact mapping is not permitted.
...
... situation much more complex. As such, the definition of this term
was revised to emphasize both the conversion aspect of the process,
and the term itself has been changed to "charset" to emphasize that
it is not, after all, just a set of characters. A discussion of
...
... Charset Registration Requirements ...
...
Registered charsets are expected to conform to a number of
requirements as described below.
...
...
Registered charsets MUST conform to the definition of a "charset"
given above. In addition, charsets ...
...
Registered charsets MUST conform to the definition of a "charset"
given above. In addition, charsets intended for use in MIME content ...
... charsets MUST conform to the definition of a "charset"
given above. In addition, charsets intended for use in MIME content
types under the "text" top-level type ...
... restrictions on that type described in RFC 2045draft. All registered
charsets MUST note whether or not they are suitable for use in MIME
text.
...
...
All registered charsets MUST be specified in a stable, openly
available specification. Registration of charsets ...
... charsets MUST be specified in a stable, openly
available specification. Registration of charsets whose
specifications aren't stable and openly available is forbidden.
...
... New Charsets ...
... This registration mechanism is not intended to be a vehicle for the
design and definition of entirely new charsets. This is due to the
fact that the registration process does NOT contain adequate review
...
...
As such, only charsets defined by other processes and standards
bodies, or specific profiles or combinations of such charsets ...
... charsets defined by other processes and standards
bodies, or specific profiles or combinations of such charsets, are
eligible for registration.
...
...
One or more names MUST be assigned to all registered charsets.
Multiple names for the same charset are permitted, but if multiple
...
... One or more names MUST be assigned to all registered charsets.
Multiple names for the same charset are permitted, but if multiple
names are assigned a single primary name for the charset MUST be
...
... Multiple names for the same charset are permitted, but if multiple
names are assigned a single primary name for the charset MUST be
identified. All other names are considered to be aliases for the
...
...
Each assigned name MUST uniquely identify a single charset. All
charset names MUST be suitable for use as the value of a MIME content ...
... Each assigned name MUST uniquely identify a single charset. All
charset names MUST be suitable for use as the value of a MIME content
type charset parameter ...
... charset names MUST be suitable for use as the value of a MIME content
type charset parameter and hence MUST conform to MIME parameter value
syntax. This applies even if the specific charset ...
... charset parameter and hence MUST conform to MIME parameter value
syntax. This applies even if the specific charset being registered
is not suitable for use with the "text" media type.
...
...
All charsets MUST be assigned a name that provides a display string
for the associated "MIBenum" value defined below. These "MIBenum"
values are defined by and used in the Printer MIB ...
... printable subset of US-ASCII. Only one name beginning with "cs" may
be assigned to a single charset. If no name of this form is
explicitly defined IANA will assign an alias ...
...
Finally, charsets being registered for use with the "text" media type
MUST have a primary name that conforms to the more restrictive syntax
...
... media type
MUST have a primary name that conforms to the more restrictive syntax
of the charset field in MIME encoded-words [RFC-2047, RFC-2184 ...
... mime-charset-chars ...
...
Charsets MUST function as actual charsets: Registration of things
that are better thought of as a transfer encoding ...
... allowed. For example, although HTML could theoretically be thought
of as a charset, it is really better thought of as a media type and
as such it cannot be registered as a charset ...
... charset, it is really better thought of as a media type and
as such it cannot be registered as a charset.
...
...
Use of a large number of charsets in a given protocol may hamper
interoperability. However, the use of a large number of undocumented
...
... interoperability. However, the use of a large number of undocumented
and/or unlabeled charsets hampers interoperability even more.
...
...
A charset should therefore be registered ONLY if it adds significant
functionality that is valuable to a large community, OR if it
...
... functionality that is valuable to a large community, OR if it
documents existing practice in a large community. Note that charsets
registered for the second reason should be explicitly marked as being
of limited or specialized use and should only be used in Internet
messages ...
...
Charset registrations MAY be published in RFCs, however, RFC
publication is not required to register ...
... registrations MAY be published in RFCs, however, RFC
publication is not required to register a new charset.
...
...
The registration of a charset does not imply endorsement, approval,
or recommendation by the IANA, IESG ...
... applicability statements for particular applications will be
published from time to time that recommend implementation of, and
support for, charsets that have proven particularly useful in those
contexts.
...
... Charset registrations SHOULD include a specification of mapping from
the charset into ISO 10646 if specification of such a mapping is
feasible.
...
...
Each registered charset MUST also be assigned a unique enumerated
integer value. These "MIBenum" values are defined by and used in the
...
... of registration. MIBenum values are not assigned by the person
registering the charset.
...
... Charset Registration Procedure ...
... The following procedure has been implemented by the IANA for review
and approval of new charsets. This is not a formal standards
process, but rather an administrative procedure intended to allow
community comment and sanity checking without excessive time delay.
...
... Present the Charset to the Community ...
... charset registration to the "ietf-
charsets@iana.org" mailing list. (Information about joining this
list is available on the IANA ...
... mailing list has been established for the sole purpose of reviewing
proposed charset registrations. Proposed charsets are not formally
...
... proposed charset registrations. Proposed charsets are not formally
registered and must not be used; the "x-" prefix specified in RFC
...
...
The posting of a charset to the list initiates a two week public
review process.
...
...
The intent of the public posting is to solicit comments and feedback
on the definition of the charset and the name chosen for it.
...
... Charset Reviewer ...
... registration
application should be submitted to IANA and the charset reviewer.
The charset reviewer, who is appointed by the IETF ...
... IANA and the charset reviewer.
The charset reviewer, who is appointed by the IETF Applications Area
Director(s), either approves the request for registration ...
... registration or rejects
it. Rejection may occur because of significant objections raised on
the list or objections raised externally. If the charset reviewer
considers the registration sufficiently important and controversial,
...
... registration sufficiently important and controversial,
a last call for comments may be issued to the full IETF. The charset
reviewer may also recommend standards track processing (before or
after registration ...
... after registration) when that appears appropriate and the level of
specification of the charset is adequate.
...
... The charset reviewer must reach a decision and post it to the ietf-
charsets mailing list within two weeks. Decisions made by the
reviewer may be appealed to the IESG ...
...
Provided that the charset registration has either passed review or
has been successfully appealed to the IESG ...
... IANA will register
the charset, assign a MIBenum value, and make its registration
available to the community.
...
... Location of Registered Charset List ...
... "ftp://ftp.isi.edu/in-notes/iana/assignments/character-sets" and all
registered charsets will be listed in the periodically issued
"Assigned Numbers" RFC [currently RFC-1700hist(-> 3232)]. The description of the
...
... "Assigned Numbers" RFC [currently RFC-1700hist(-> 3232)]. The description of the
charset MAY also be published as an Informational RFC by sending it
to "rfc-editor@isi.edu" (please follow the instructions to RFC
authors [RFC-1543 ...
... Charset Registration Template ...
... Published specification(s):
(A specification for the charset MUST be
openly available that accurately describes what
is being registered. If a charset ...
... charset MUST be
openly available that accurately describes what
is being registered. If a charset is defined as
a composition of one or more CCS's and a CES ...
... (A URI to a specification of how to translate from
this charset to ISO 10646 and vice versa SHOULD be
provided.)
...
... security considerations that are appreciably different from those
already existing in the protocols that employ registered charsets.
...
... Inclusion of a mapping to ISO 10646 is now recommended for all
registered charsets. The registration template has been updated to
include this as well as a place to indicate whether or not the
...
... registration template has been updated to
include this as well as a place to indicate whether or not the
charset is suitable for use in MIME text.
...