網絡協(xié)議分析

1、語言鑒定標簽語言鑒定標簽喻清源 目錄!1介紹!2語言標簽!3語言標簽的IANA 注冊過程!4安全因素!5符號集合問題!6鳴謝!7作者地址!8參考文獻1介紹!在我們這個星球上生存的人，過去的、現(xiàn)在的，已經使用了很多種語言。有很多原因使得我們必須在傳送信息時確認所使用的語言。在有些時候，用多于一種語言描述信息也可行的，或者當提供了工具（比如字典）來輔助理解時也是可行的。另外，很多類型的信息處理都需要相應語言的知識，以便明確的闡釋信息，進行處理。 1Introduction!Human beings on our planet have, past and present, used a numbe

2、r of languages. There are many reasons why one would want to identify the language used when presenting information.In some contexts, it is possible to have information available in more than one language, or it might be possible to provide tools (such as dictionaries) to assist in the understanding

3、 of a language.2語言標簽!21 語言標簽語法!22 語言標簽來源!23 語言標簽的選擇!24 語言標簽的意義!25 語言范圍21 語言標簽語法這種語言標簽是由一或幾部分構成的：一個主要語言輔標簽（subtag），一系列（可能是空的）副標簽(subsequent subtags)。 22 語言標簽來源!根據本文檔第三部分的規(guī)定，語言標簽的名字域由IANA(Internet Assigned Numbers !Authority，見rfc 2860)管理。!下列規(guī)則適用于主要的標簽：!-根據ISO 標準639中的分配，所有的含2個字母的標簽被解釋為，“表示語言中的名!稱”（見ISO

4、 639），或是稍后被分配為維護和調節(jié)的標準體（注意，有一處校正尚未完成，!它將在ISO 639-1:2000中發(fā)布）。23 語言標簽的選擇!我們可能會偶爾遇到同樣的文本有幾種可能的標簽的情況。!如果所有的用戶發(fā)送同樣的標簽，在所有的文檔中使用同一種語言的標簽，那將是再好!不過的事了。如果應用程序有需要使這些規(guī)則在特定場合不適用，則應用協(xié)議必須指明是如!何變化的。24 語言標簽的意義!語言標簽總是定義一種語言，作為口語（書寫語，標志，或者是信號）供人類進行交流與傳遞信息。計算機語言比如程序設計語言被明確的排除在外。沒有什么可以保證有同樣標簽的語言之間的關系；特別地，也不能保證它們（語言）見可以

5、相互理解，盡管有時是可以的。25 語言范圍!如果一個用戶理解了一種特定的標簽語言，那么，他將理解所有的以這種標簽為前綴的語言）被分配到具體的語言，既不總是那么容易觸類旁通的。一般來講，前綴規(guī)則允許用戶用這種前綴標簽，在適當條件下。2.1 Language tag syntax!The language tag is composed of one or more parts: A primary language subtag and a (possibly empty) series of subsequent subtags.2.2 Language tag sources! The na

6、mespace of language tags is administered by the Internet Assigned Numbers Authority (IANA) RFC 2860 according to the rules in section 3 of this document.2.3 Choice of language tag! One may occasionally be faced with several possible tags for the same body of text.nteroperability is best served if al

7、l users send the same tag, and use the same tag for the same language for all documents. If an application has requirements that make the rules here inapplicable,the application protocol specification MUST specify how the procedure varies from the one given here.2.4 Meaning of the language tag! The

8、language tag always defines a language as spoken (or written, signed or otherwise signaled) by human beings for communication of information to other human beings. Computer languages such as programming languages are explicitly excluded. There is no guaranteed relationship between languages whose ta

9、gs begin with the same series of subtags; specifically, they are NOT guaranteed to be mutually intelligible, although it will sometimes be the case that they are.2.5 Language-range!This use of a prefix matching rule does not imply that language tags are assigned to languages in such a way that it is

10、 always true that if a user understands a language with a certain tag, then this user will also understand all languages with tags for which this tag is a prefix. The prefix rule simply allows the use of prefix tags if this is the case.3 語言標簽的IANA 注冊過程!任何人想要使用標簽，包括在本文檔2。2章沒給出解釋的，和已經注冊IANA的，都必須要用到這里給

11、出的過程。3. IANA registration procedure for language tags The procedure given here MUST be used by anyone who wants to use a language tag not given an interpretation in chapter 2.2 of this document or previously registered with IANA4安全因素!關于語言標簽安全問題的唯一的一份論文（自RFC 1766 發(fā)布以來），聲明了“安全問題必將與此備忘錄無關“，也講到了關于語言范圍的令

12、人滿意的協(xié)商結論忽略發(fā)送者的國籍，也因此為監(jiān)視確定了潛在的目標。4. Security Considerations!The only security issue that has been raised with language tags since the publication of RFC 1766, which stated that Security issues are believed to be irrelevant to this memo, is a concern with language ranges used in content negotiation -

13、that they may be used to infer the nationality of the sender, and thus identify potential targets for surveillance5 符號集合問題!語言標簽可以總是以A-Z,a-z,0-9,和連詞符號（HYPHEN-MINUS）表示，所以在語言標簽的表示上不會有字符集合的問題爭論。決定語言標簽所使用的字符集的問題在這個備忘錄中沒有提到；然而，作出一個適于所有情況的正確的決定被認為將是不可能的，除非在文中更換語言時有相應的定義。（當決定一個引擎的字體是中文或是日文時，就會產生次最佳輸出，就會遇到中日

14、文混合的文本）。5. Character set considerations! Language tags may always be presented using the characters A-Z, a-z, 0-9 and HYPHEN-MINUS, which are present in most character sets, so presentation of language tags should not have any character set issues.This document has benefited from many rounds of revi

15、ew and comment in various fora of the IETF and the Internet working groups.Any list of contributors is bound to be incomplete; please regard the following as only a selection from the group of people who have contributed to make this document what it is today.In alphabetical order:Glenn Adams, Tim B

16、erners-Lee, Marc Blanchet, Nathaniel Borenstein,Eric Brunner, Sean M. Burke, John Clews, Jim Conklin, Peter Constable, John Cowan, Mark Crispin, Dave Crocker, Mark Davis, Martin Duerst, Michael Everson, Ned Freed, Tim Goodwin, Dirk-Willem van Gulik, Marion Gunn, Paul Hoffman, Olle Jarnefors, Kent Ka

17、rlsson, John Klensin, Alain LaBonte, Chris Newman, Keith Moore, Masataka Ohta,Keld Jorn Simonsen, Otto Stolz, Rhys Weatherley, Misha Wolf, FrancoisYergeau and many, many others.Special thanks must go to Michael Everson, who has served as language tag reviewer for almost the complete period since the

18、 publication of RFC 1766, and has provided a great deal of input to this revision.7作者地址! Harald Tveit Alvestrand! Cisco Systems! Weidemanns vei 27! 7043 Trondheim! NORWAY! Phone: +47 73 50 33 52! EMail: HaraldAlvestrand.no8參考文獻! ISO 639 ISO 639:1988 (E/F) - Code for the representation of names! of l

19、anguages - The International Organization for! Standardization, 1st edition, 1988-04-01 Prepared by! ISO/TC 37 - Terminology (principles and coordination).! Note that a new version (ISO 639-1:2000) is in! preparation at the time of this writing.!ISO 639-2 ISO 639-2:1998 - Codes for the representatio

20、n of names of! languages - Part 2: Alpha-3 code - edition 1, 1998-11-! 01, 66 pages, prepared by a Joint Working Group of ISO! TC46/SC4 and ISO TC37/SC2.!ISO 3166 ISO 3166:1988 (E/F) - Codes for the representation of! names of countries - The International Organization for! Standardization, 3rd edit

21、ion, 1988-08-15.!RFC 1327 Kille, S., Mapping between X.400 (1988) / ISO 10021 and! RFC 822, RFC 1327, May 1992.!RFC 1521 Borenstein, N., and N. Freed, MIME Part One: Mechanisms! for Specifying and Describing the Format of Internet! Message Bodies, RFC 1521, September 1993!RFC 2026 Bradner, S., The Internet Standards Process - Revision! 3, BCP 9, RFC 2026, Octo