2. Where to do internationalization どこを国際化するのか

   Internationalization is for humans. This means that protocols are not
   subject to internationalization; text strings are. Where protocol
   elements look like text tokens, such as in many IETF application
   layer protocols, protocols MUST specify which parts are protocol and
   which are text. [WR 2.2.1.1]

国際化は人間のためのものです。これはプロトコルは国際化の 対象ではなく、文字列は対象であることを意味します。 文字字句のように見えるプロトコル要素は多くの IETF 応用層プロトコルなどに見られますが、プロトコルはどの部分が プロトコルであってどの部分が文字なのかを規定しなければなりません。

(訳注: 言いたいことはわかるけど、プロトコルという語が 2種類の意味で使われててよくないと思う。)

Names are a problem, because people feel strongly about them, many of them are mostly for local usage, and all of them tend to leak out of the local context at times. RFC 1958 [RFC 1958] recommends US-ASCII for all globally visible names.

名前は問題で、人々は強い感情を持っており、その多くはほとんど local で使われていて、その全てが時々 local な文脈から 漏れ出す傾向にあります。 RFC 1958 は全ての global に可視な名前に US-ASCII を推奨しています。

   This document does not mandate a policy on name internationalization,
   but requires that all protocols describe whether names are
   internationalized or US-ASCII.

この文書は名前の国際化の方針を強制しませんが、プロトコルは 名前を国際化するか US-ASCII かを述べる必要があります。

NOTE: In the protocol stack for any given application, there is usually one or a few layers that need to address these problems.

任意の応用のプロトコル・スタックにおいて、一般にこの問題に 言及する必要のあるのは1つか2つ,3つの層です。

It would, for instance, not be appropriate to define language tags for Ethernet frames. But it is the responsibility of the WGs to ensure that whenever responsibility for internationalization is left to "another layer", those responsible for that layer are in fact aware that they HAVE that responsibility.

例えば、 Ethernet の枠組みで言語札を定義するのは 適切ではないでしょう。しかし国際化の責任が「他の層」に渡っている 時はいつも、その層の責任は実際その WG が責任を 負っているのを確かにするのは WG の責任です。

(訳注: よくわかりません。 )

3. Definition of Terms 用語の定義

   This document uses the term "charset" to mean a set of rules for
   mapping from a sequence of octets to a sequence of characters, such
   as the combination of a coded character set and a character encoding
   scheme; this is also what is used as an identifier in MIME "charset="
   parameters, and registered in the IANA charset registry [REG].  (Note
   that this is NOT a term used by other standards bodies, such as ISO).

   For a definition of the term "coded character set", refer to the
   workshop report.

   A "name" is an identifier such as a person's name, a hostname, a
   domainname, a filename or an E-mail address; it is often treated as
   an identifier rather than as a piece of text, and is often used in
   protocols as an identifier for entities, without surrounding text.

3.1. What charset to use

   All protocols MUST identify, for all character data, which charset is
   in use.

Alvestrand Best Current Practice [Page 2]  RFC 2277 Charset Policy January 1998

   Protocols MUST be able to use the UTF-8 charset, which consists of
   the ISO 10646 coded character set combined with the UTF-8 character
   encoding scheme, as defined in [10646] Annex R (published in
   Amendment 2), for all text.

   Protocols MAY specify, in addition, how to use other charsets or
   other character encoding schemes for ISO 10646, such as UTF-16, but
   lack of an ability to use UTF-8 is a violation of this policy; such a
   violation would need a variance procedure ([BCP9] section 9) with
   clear and solid justification in the protocol specification document
   before being entered into or advanced upon the standards track.

   For existing protocols or protocols that move data from existing
   datastores, support of other charsets, or even using a default other
   than UTF-8, may be a requirement. This is acceptable, but UTF-8
   support MUST be possible.

   When using other charsets than UTF-8, these MUST be registered in the
   IANA charset registry, if necessary by registering them when the
   protocol is published.

   (Note: ISO 10646 calls the UTF-8 CES a "Transformation Format" rather
   than a "character encoding scheme", but it fits the charset workshop
   report definition of a character encoding scheme).

3.2. How to decide a charset

   When the protocol allows a choice of multiple charsets, someone must
   make a decision on which charset to use.

   In some cases, like HTTP, there is direct or semi-direct
   communication between the producer and the consumer of data
   containing text. In such cases, it may make sense to negotiate a
   charset before sending data.

   In other cases, like E-mail or stored data, there is no such
   communication, and the best one can do is to make sure the charset is
   clearly identified with the stored data, and choosing a charset that
   is as widely known as possible.

   Note that a charset is an absolute; text that is encoded in a charset
   cannot be rendered comprehensibly without supporting that charset.

   (This also applies to English texts; charsets like EBCDIC do NOT have
   ASCII as a proper subset)

Alvestrand Best Current Practice [Page 3]  RFC 2277 Charset Policy January 1998

   Negotiating a charset may be regarded as an interim mechanism that is
   to be supported until support for interchange of UTF-8 is prevalent;
   however, the timeframe of "interim" may be at least 50 years, so
   there is every reason to think of it as permanent in practice.

4.1. The need for language information

   All human-readable text has a language.

   Many operations, including high quality formatting, text-to-speech
   synthesis, searching, hyphenation, spellchecking and so on benefit
   greatly from access to information about the language of a piece of
   text. [WC 3.1.1.4].

   Humans have some tolerance for foreign languages, but are generally
   very unhappy with being presented text in a language they do not
   understand; this is why negotiation of language is needed.

   In most cases, machines will not be able to deduce the language of a
   transmitted text by themselves; the protocol must specify how to
   transfer the language information if it is to be available at all.

   The interaction between language and processing is complex; for
   instance, if I compare "name-of-thing(lang=en)" to "name-of-
   thing(lang=no)" for equality, I will generally expect a match, while
   the word "ask(no)" is a kind of tree, and is hardly useful as a
   command verb.

4.2. Requirement for language tagging

   Protocols that transfer text MUST provide for carrying information
   about the language of that text.

   Protocols SHOULD also provide for carrying information about the
   language of names, where appropriate.

   Note that this does NOT mean that such information must always be
   present; the requirement is that if the sender of information wishes
   to send information about the language of a text, the protocol
   provides a well-defined way to carry this information.

Alvestrand Best Current Practice [Page 4]  RFC 2277 Charset Policy January 1998

4.3. How to identify a language

   The RFC 1766 language tag is at the moment the most flexible tool
   available for identifying a language; protocols SHOULD use this, or
   provide clear and solid justification for doing otherwise in the
   document.

   Note also that a language is distinct from a POSIX locale; a POSIX
   locale identifies a set of cultural conventions, which may imply a
   language (the POSIX or "C" locale of course do not), while a language
   tag as described in RFC 1766 identifies only a language.

4.4. Considerations for language negotiation

   Protocols where users have text presented to them in response to user
   actions MUST provide for support of multiple languages.

   How this is done will vary between protocols; for instance, in some
   cases, a negotiation where the client proposes a set of languages and
   the server replies with one is appropriate; in other cases, a server
   may choose to send multiple variants of a text and let the client
   pick which one to display.

   Negotiation is useful in the case where one side of the protocol
   exchange is able to present text in multiple languages to the other
   side, and the other side has a preference for one of these; the most
   common example is the text part of error responses, or Web pages that
   are available in multiple languages.

   Negotiating a language should be regarded as a permanent requirement
   of the protocol that will not go away at any time in the future.

   In many cases, it should be possible to include it as part of the
   connection establishment, together with authentication and other
   preferences negotiation.

4.5. Default Language 既定言語

When human-readable text must be presented in a context where the sender has no knowledge of the recipient's language preferences (such as login failures or E-mailed warnings, or prior to language negotiation), text SHOULD be presented in Default Language.

[10647] 人間可読textが、送信者が受信者の言語の好みについて何の知識もない場面で表現されなければならない時 (例えばログイン失敗や電子メイルで送られる警告又は言語折衝以前) には、textは既定言語で表現するSHOULD。

Default Language is assigned the tag "i-default" according to the procedures of RFC 1766. It is not a specific language, but rather identifies the condition where the language preferences of the user cannot be established.

既定言語 には RFC1766 の手続きに従ってtag "i-default" を割当てます。これは言語を特定せず、むしろ利用者の言語の好みが特定できない状態を識別します。

Messages in Default Language MUST be understandable by an English-speaking person, since English is the language which, worldwide, the greatest number of people will be able to get adequate help in interpreting when working with computers.

既定言語でのメッセージは英語話者に理解可能でなければMUST。 なぜなら、英語は世界中で最も沢山の人々が計算機で作業している時に解釈する助けを得ることが出来るであろうからです。

Note that negotiating English is NOT the same as Default Language; Default Language is an emergency measure in otherwise unmanageable situations.

なお、英語に折衝することは既定言語と同じではありません。 既定言語はそうでなければ扱いにくい状態の非常のものです。

In many cases, using only English text is reasonable; in some cases, the English text may be augumented by text in other languages.

多くの場合、英語だけのtextを使うのが適当です。 英語textが他の言語のtextで補われる場合もあり得ます。

10. Full Copyright Statement

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

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