Internet Engineering Task Force (IETF) J. Reschke
Request for Comments: 5987 greenbytes
Category: Standards Track August 2010
ISSN: 2070-1721
Internet Engineering Task Force (IETF) J. Reschke
Request for Comments: 5987 greenbytes
Category: Standards Track August 2010
ISSN: 2070-1721
Character Set and Language Encoding for Hypertext Transfer Protocol (HTTP) Header Field Parameters
超文本传输协议（HTTP）头字段参数的字符集和语言编码
Abstract
摘要
By default, message header field parameters in Hypertext Transfer Protocol (HTTP) messages cannot carry characters outside the ISO-8859-1 character set. RFC 2231 defines an encoding mechanism for use in Multipurpose Internet Mail Extensions (MIME) headers. This document specifies an encoding suitable for use in HTTP header fields that is compatible with a profile of the encoding defined in RFC 2231.
默认情况下，超文本传输协议（HTTP）消息中的消息头字段参数不能携带ISO-8859-1字符集之外的字符。RFC 2231定义了一种用于多用途Internet邮件扩展（MIME）头的编码机制。本文档指定了适合在HTTP头字段中使用的编码，该编码与RFC 2231中定义的编码配置文件兼容。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc5987.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc5987.
Copyright Notice
版权公告
Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2010 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................2
2. Notational Conventions ..........................................2
3. Comparison to RFC 2231 and Definition of the Encoding ...........3
3.1. Parameter Continuations ....................................3
3.2. Parameter Value Character Set and Language Information .....3
3.2.1. Definition ..........................................3
3.2.2. Examples ............................................6
3.3. Language Specification in Encoded Words ....................6
4. Guidelines for Usage in HTTP Header Field Definitions ...........7
4.1. When to Use the Extension ..................................7
4.2. Error Handling .............................................7
5. Security Considerations .........................................8
6. Acknowledgements ................................................8
7. References ......................................................8
7.1. Normative References .......................................8
7.2. Informative References .....................................9
1. Introduction ....................................................2
2. Notational Conventions ..........................................2
3. Comparison to RFC 2231 and Definition of the Encoding ...........3
3.1. Parameter Continuations ....................................3
3.2. Parameter Value Character Set and Language Information .....3
3.2.1. Definition ..........................................3
3.2.2. Examples ............................................6
3.3. Language Specification in Encoded Words ....................6
4. Guidelines for Usage in HTTP Header Field Definitions ...........7
4.1. When to Use the Extension ..................................7
4.2. Error Handling .............................................7
5. Security Considerations .........................................8
6. Acknowledgements ................................................8
7. References ......................................................8
7.1. Normative References .......................................8
7.2. Informative References .....................................9
By default, message header field parameters in HTTP ([RFC2616]) messages cannot carry characters outside the ISO-8859-1 character set ([ISO-8859-1]). RFC 2231 ([RFC2231]) defines an encoding mechanism for use in MIME headers. This document specifies an encoding suitable for use in HTTP header fields that is compatible with a profile of the encoding defined in RFC 2231.
默认情况下，HTTP（[RFC2616]）消息中的消息头字段参数不能携带ISO-8859-1字符集（[ISO-8859-1]）之外的字符。RFC 2231（[RFC2231]）定义了用于MIME头的编码机制。本文档指定了适合在HTTP头字段中使用的编码，该编码与RFC 2231中定义的编码配置文件兼容。
Note: in the remainder of this document, RFC 2231 is only referenced for the purpose of explaining the choice of features that were adopted; they are therefore purely informative.
注：在本文件的其余部分中，RFC 2231仅用于解释所采用特征的选择；因此，它们纯粹是信息性的。
Note: this encoding does not apply to message payloads transmitted over HTTP, such as when using the media type "multipart/form-data" ([RFC2388]).
注意：此编码不适用于通过HTTP传输的消息有效负载，例如使用媒体类型“multipart/form data”（[RFC2388]）。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
This specification uses the ABNF (Augmented Backus-Naur Form) notation defined in [RFC5234]. The following core rules are included by reference, as defined in [RFC5234], Appendix B.1: ALPHA (letters), DIGIT (decimal 0-9), HEXDIG (hexadecimal 0-9/A-F/a-f), and LWSP (linear whitespace).
本规范使用[RFC5234]中定义的ABNF（增强的巴科斯-诺尔形式）表示法。参考[RFC5234]附录B.1中定义的以下核心规则：字母（字母）、数字（十进制0-9）、十六进制数字（十六进制0-9/A-F/A-F）和LWSP（线性空白）。
Note that this specification uses the term "character set" for consistency with other IETF specifications such as RFC 2277 (see [RFC2277], Section 3). A more accurate term would be "character encoding" (a mapping of code points to octet sequences).
注意，本规范使用术语“字符集”与其他IETF规范（如RFC 2277）保持一致（见[RFC2277]，第3节）。更准确的术语是“字符编码”（代码点到八位字节序列的映射）。
RFC 2231 defines several extensions to MIME. The sections below discuss if and how they apply to HTTP header fields.
RFC 2231定义了MIME的几个扩展。以下各节讨论它们是否以及如何应用于HTTP头字段。
In short:
简言之：
o Parameter Continuations aren't needed (Section 3.1),
o 不需要参数延续（第3.1节），
o Character Set and Language Information are useful, therefore a simple subset is specified (Section 3.2), and
o 字符集和语言信息非常有用，因此指定了一个简单子集（第3.2节），并且
o Language Specifications in Encoded Words aren't needed (Section 3.3).
o 不需要编码单词中的语言规范（第3.3节）。
Section 3 of [RFC2231] defines a mechanism that deals with the length limitations that apply to MIME headers. These limitations do not apply to HTTP ([RFC2616], Section 19.4.7).
[RFC2231]的第3节定义了一种处理适用于MIME头的长度限制的机制。这些限制不适用于HTTP（[RFC2616]，第19.4.7节）。
Thus, parameter continuations are not part of the encoding defined by this specification.
因此，参数连续性不是本规范定义的编码的一部分。
Section 4 of [RFC2231] specifies how to embed language information into parameter values, and also how to encode non-ASCII characters, dealing with restrictions both in MIME and HTTP header parameters.
[RFC2231]的第4节规定了如何将语言信息嵌入参数值，以及如何编码非ASCII字符，以处理MIME和HTTP头参数中的限制。
However, RFC 2231 does not specify a mandatory-to-implement character set, making it hard for senders to decide which character set to use. Thus, recipients implementing this specification MUST support the character sets "ISO-8859-1" [ISO-8859-1] and "UTF-8" [RFC3629].
但是，RFC 2231没有指定实现字符集的强制命令，这使得发送者很难决定使用哪个字符集。因此，实现本规范的收件人必须支持字符集“ISO-8859-1”[ISO-8859-1]和“UTF-8”[RFC3629]。
Furthermore, RFC 2231 allows the character set information to be left out. The encoding defined by this specification does not allow that.
此外，RFC 2231允许省略字符集信息。本规范定义的编码不允许这样做。
The syntax for parameters is defined in Section 3.6 of [RFC2616] (with RFC 2616 implied LWS translated to RFC 5234 LWSP):
[RFC2616]第3.6节中定义了参数语法（RFC 2616隐含LWS转换为RFC 5234 LWSP）：
parameter = attribute LWSP "=" LWSP value
参数=属性LWSP“=”LWSP值
attribute = token value = token / quoted-string
属性=标记值=标记/带引号的字符串
quoted-string = <quoted-string, defined in [RFC2616], Section 2.2>
token = <token, defined in [RFC2616], Section 2.2>
quoted-string = <quoted-string, defined in [RFC2616], Section 2.2>
token = <token, defined in [RFC2616], Section 2.2>
In order to include character set and language information, this specification modifies the RFC 2616 grammar to be:
为了包含字符集和语言信息，本规范将RFC 2616语法修改为：
parameter = reg-parameter / ext-parameter
parameter = reg-parameter / ext-parameter
reg-parameter = parmname LWSP "=" LWSP value
reg参数=参数名称LWSP“=”LWSP值
ext-parameter = parmname "*" LWSP "=" LWSP ext-value
ext-parameter = parmname "*" LWSP "=" LWSP ext-value
parmname = 1*attr-char
parmname = 1*attr-char
ext-value = charset "'" [ language ] "'" value-chars
; like RFC 2231's <extended-initial-value>
; (see [RFC2231], Section 7)
ext-value = charset "'" [ language ] "'" value-chars
; like RFC 2231's <extended-initial-value>
; (see [RFC2231], Section 7)
charset = "UTF-8" / "ISO-8859-1" / mime-charset
charset = "UTF-8" / "ISO-8859-1" / mime-charset
mime-charset = 1*mime-charsetc
mime-charsetc = ALPHA / DIGIT
/ "!" / "#" / "$" / "%" / "&"
/ "+" / "-" / "^" / "_" / "`"
/ "{" / "}" / "~"
; as <mime-charset> in Section 2.3 of [RFC2978]
; except that the single quote is not included
; SHOULD be registered in the IANA charset registry
mime-charset = 1*mime-charsetc
mime-charsetc = ALPHA / DIGIT
/ "!" / "#" / "$" / "%" / "&"
/ "+" / "-" / "^" / "_" / "`"
/ "{" / "}" / "~"
; as <mime-charset> in Section 2.3 of [RFC2978]
; except that the single quote is not included
; SHOULD be registered in the IANA charset registry
language = <Language-Tag, defined in [RFC5646], Section 2.1>
language = <Language-Tag, defined in [RFC5646], Section 2.1>
value-chars = *( pct-encoded / attr-char )
value-chars = *( pct-encoded / attr-char )
pct-encoded = "%" HEXDIG HEXDIG ; see [RFC3986], Section 2.1
pct编码=“%”HEXDIG HEXDIG；参见[RFC3986]，第2.1节
attr-char = ALPHA / DIGIT
/ "!" / "#" / "$" / "&" / "+" / "-" / "."
/ "^" / "_" / "`" / "|" / "~"
; token except ( "*" / "'" / "%" )
attr-char = ALPHA / DIGIT
/ "!" / "#" / "$" / "&" / "+" / "-" / "."
/ "^" / "_" / "`" / "|" / "~"
; token except ( "*" / "'" / "%" )
Thus, a parameter is either a regular parameter (reg-parameter), as previously defined in Section 3.6 of [RFC2616], or an extended parameter (ext-parameter).
因此，参数可以是[RFC2616]第3.6节中先前定义的常规参数（reg参数），也可以是扩展参数（ext参数）。
Extended parameters are those where the left-hand side of the assignment ends with an asterisk character.
扩展参数是指赋值的左侧以星号字符结尾的参数。
The value part of an extended parameter (ext-value) is a token that consists of three parts: the REQUIRED character set name (charset), the OPTIONAL language information (language), and a character sequence representing the actual value (value-chars), separated by single quote characters. Note that both character set names and language tags are restricted to the US-ASCII character set, and are matched case-insensitively (see [RFC2978], Section 2.3 and [RFC5646], Section 2.1.1).
扩展参数（ext value）的值部分是一个标记，由三部分组成：所需的字符集名称（charset）、可选语言信息（language）和表示实际值的字符序列（value chars），由单引号字符分隔。请注意，字符集名称和语言标记均限于US-ASCII字符集，且大小写匹配不敏感（请参阅[RFC2978]，第2.3节和[RFC5646]，第2.1.1节）。
Inside the value part, characters not contained in attr-char are encoded into an octet sequence using the specified character set. That octet sequence is then percent-encoded as specified in Section 2.1 of [RFC3986].
在值部分中，使用指定的字符集将attr char中未包含的字符编码为八位字节序列。然后按照[RFC3986]第2.1节的规定对该八位组序列进行百分比编码。
Producers MUST use either the "UTF-8" ([RFC3629]) or the "ISO-8859-1" ([ISO-8859-1]) character set. Extension character sets (mime-charset) are reserved for future use.
生产者必须使用“UTF-8”（[RFC3629]）或“ISO-8859-1”（[ISO-8859-1]）字符集。扩展字符集（mime字符集）保留供将来使用。
Note: recipients should be prepared to handle encoding errors, such as malformed or incomplete percent escape sequences, or non-decodable octet sequences, in a robust manner. This specification does not mandate any specific behavior, for instance, the following strategies are all acceptable:
注意：接收者应准备好以稳健的方式处理编码错误，例如错误的或不完整的百分比转义序列，或不可解码的八位字节序列。本规范不强制要求任何特定行为，例如，以下策略都是可接受的：
* ignoring the parameter,
* 忽略参数，
* stripping a non-decodable octet sequence,
* 剥离不可解码的八位组序列，
* substituting a non-decodable octet sequence by a replacement character, such as the Unicode character U+FFFD (Replacement Character).
* 用替换字符替换不可解码的八位字节序列，例如Unicode字符U+FFFD（替换字符）。
Note: the RFC 2616 token production ([RFC2616], Section 2.2) differs from the production used in RFC 2231 (imported from Section 5.1 of [RFC2045]) in that curly braces ("{" and "}") are excluded. Thus, these two characters are excluded from the attr-char production as well.
注：RFC 2616令牌生成（[RFC2616]，第2.2节）与RFC 2231（从[RFC2045]第5.1节导入）中使用的生成不同，因为不包括花括号（“{”和“}”）。因此，这两个字符也被排除在attr char生成之外。
Note: the <mime-charset> ABNF defined here differs from the one in Section 2.3 of [RFC2978] in that it does not allow the single quote character (see also RFC Errata ID 1912 [Err1912]). In practice, no character set names using that character have been registered at the time of this writing.
注：此处定义的<mime字符集>ABNF与[RFC2978]第2.3节中的不同之处在于它不允许使用单引号字符（另请参见RFC勘误表ID 1912[Err1912]）。实际上，在撰写本文时，尚未注册使用该字符的字符集名称。
Non-extended notation, using "token":
使用“标记”的非扩展表示法：
foo: bar; title=Economy
foo: bar; title=Economy
Non-extended notation, using "quoted-string":
使用“带引号的字符串”的非扩展表示法：
foo: bar; title="US-$ rates"
foo: bar; title="US-$ rates"
Extended notation, using the Unicode character U+00A3 (POUND SIGN):
扩展符号，使用Unicode字符U+00A3（磅符号）：
foo: bar; title*=iso-8859-1'en'%A3%20rates
foo: bar; title*=iso-8859-1'en'%A3%20rates
Note: the Unicode pound sign character U+00A3 was encoded into the single octet A3 using the ISO-8859-1 character encoding, then percent-encoded. Also, note that the space character was encoded as %20, as it is not contained in attr-char.
注意：Unicode磅符号字符U+00A3使用ISO-8859-1字符编码编码到单个八位字节A3中，然后进行百分比编码。另外，请注意空格字符编码为%20，因为它不包含在attr char中。
Extended notation, using the Unicode characters U+00A3 (POUND SIGN) and U+20AC (EURO SIGN):
扩展符号，使用Unicode字符U+00A3（磅符号）和U+20AC（欧元符号）：
foo: bar; title*=UTF-8''%c2%a3%20and%20%e2%82%ac%20rates
foo: bar; title*=UTF-8''%c2%a3%20and%20%e2%82%ac%20rates
Note: the Unicode pound sign character U+00A3 was encoded into the octet sequence C2 A3 using the UTF-8 character encoding, then percent-encoded. Likewise, the Unicode euro sign character U+20AC was encoded into the octet sequence E2 82 AC, then percent-encoded. Also note that HEXDIG allows both lowercase and uppercase characters, so recipients must understand both, and that the language information is optional, while the character set is not.
注意：Unicode磅符号字符U+00A3使用UTF-8字符编码编码到八位字节序列C2 A3中，然后进行百分比编码。同样，Unicode欧洲符号字符U+20AC被编码到八位字节序列E282 AC中，然后进行百分比编码。还请注意，HEXDIG同时允许小写和大写字符，因此收件人必须同时理解这两种字符，并且语言信息是可选的，而字符集不是。
Section 5 of [RFC2231] extends the encoding defined in [RFC2047] to also support language specification in encoded words. Although the HTTP/1.1 specification does refer to RFC 2047 ([RFC2616], Section 2.2), it's not clear to which header field exactly it applies, and whether it is implemented in practice (see <http://tools.ietf.org/wg/httpbis/trac/ticket/111> for details).
[RFC2231]第5节扩展了[RFC2047]中定义的编码，以支持编码字中的语言规范。尽管HTTP/1.1规范确实参考了RFC 2047（[RFC2616]，第2.2节），但不清楚它究竟适用于哪个报头字段，以及它是否在实践中实现（参见<http://tools.ietf.org/wg/httpbis/trac/ticket/111>详细信息）。
Thus, this specification does not include this feature.
因此，本规范不包括该特性。
Specifications of HTTP header fields that use the extensions defined in Section 3.2 ought to clearly state that. A simple way to achieve this is to normatively reference this specification, and to include the ext-value production into the ABNF for that header field.
使用第3.2节中定义的扩展的HTTP头字段的规范应该清楚地说明这一点。实现这一点的一个简单方法是规范地引用此规范，并将ext值生成包含到该头字段的ABNF中。
For instance:
例如：
foo-header = "foo" LWSP ":" LWSP token ";" LWSP title-param
title-param = "title" LWSP "=" LWSP value
/ "title*" LWSP "=" LWSP ext-value
ext-value = <see RFC 5987, Section 3.2>
foo-header = "foo" LWSP ":" LWSP token ";" LWSP title-param
title-param = "title" LWSP "=" LWSP value
/ "title*" LWSP "=" LWSP ext-value
ext-value = <see RFC 5987, Section 3.2>
Note: The Parameter Value Continuation feature defined in Section 3 of [RFC2231] makes it impossible to have multiple instances of extended parameters with identical parmname components, as the processing of continuations would become ambiguous. Thus, specifications using this extension are advised to disallow this case for compatibility with RFC 2231.
注：[RFC2231]第3节中定义的参数值连续性功能使得扩展参数的多个实例不可能具有相同的parmname组件，因为连续性的处理将变得不明确。因此，为了与RFC 2231兼容，建议使用此扩展的规范不允许这种情况。
Section 4.2 of [RFC2277] requires that protocol elements containing human-readable text are able to carry language information. Thus, the ext-value production ought to be always used when the parameter value is of textual nature and its language is known.
[RFC2277]第4.2节要求包含人类可读文本的协议元素能够携带语言信息。因此，当参数值具有文本性质且其语言已知时，应始终使用ext值生成。
Furthermore, the extension ought to also be used whenever the parameter value needs to carry characters not present in the US-ASCII ([USASCII]) character set (note that it would be unacceptable to define a new parameter that would be restricted to a subset of the Unicode character set).
此外，当参数值需要携带US-ASCII（[USASCII]）字符集中不存在的字符时，也应该使用扩展名（请注意，定义一个新参数将被限制为Unicode字符集的子集是不可接受的）。
Header field specifications need to define whether multiple instances of parameters with identical parmname components are allowed, and how they should be processed. This specification suggests that a parameter using the extended syntax takes precedence. This would allow producers to use both formats without breaking recipients that do not understand the extended syntax yet.
标题字段规范需要定义是否允许具有相同parmname组件的参数的多个实例，以及如何处理它们。此规范建议使用扩展语法的参数优先。这将允许生产者使用这两种格式，而不会打断还不理解扩展语法的接收者。
Example:
例子：
foo: bar; title="EURO exchange rates";
title*=utf-8''%e2%82%ac%20exchange%20rates
foo: bar; title="EURO exchange rates";
title*=utf-8''%e2%82%ac%20exchange%20rates
In this case, the sender provides an ASCII version of the title for legacy recipients, but also includes an internationalized version for recipients understanding this specification -- the latter obviously ought to prefer the new syntax over the old one.
在这种情况下，发送方为遗留收件人提供了一个ASCII版本的标题，但也为理解此规范的收件人提供了一个国际化版本——后者显然应该更喜欢新语法而不是旧语法。
Note: at the time of this writing, many implementations failed to ignore the form they do not understand, or prioritize the ASCII form although the extended syntax was present.
注意：在撰写本文时，尽管存在扩展语法，但许多实现未能忽略他们不理解的形式，也未能优先考虑ASCII形式。
The format described in this document makes it possible to transport non-ASCII characters, and thus enables character "spoofing" scenarios, in which a displayed value appears to be something other than it is.
本文档中描述的格式使传输非ASCII字符成为可能，从而支持字符“欺骗”场景，其中显示的值似乎与实际值不同。
Furthermore, there are known attack scenarios relating to decoding UTF-8.
此外，存在与解码UTF-8相关的已知攻击场景。
See Section 10 of [RFC3629] for more information on both topics.
有关这两个主题的更多信息，请参见[RFC3629]第10节。
In addition, the extension specified in this document makes it possible to transport multiple language variants for a single parameter, and such use might allow spoofing attacks, where different language versions of the same parameter are not equivalent. Whether this attack is useful as an attack depends on the parameter specified.
此外，本文档中指定的扩展允许为单个参数传输多个语言变体，并且这种使用可能允许欺骗攻击，其中同一参数的不同语言版本并不等效。此攻击作为攻击是否有用取决于指定的参数。
Thanks to Martin Duerst and Frank Ellermann for help figuring out ABNF details, to Graham Klyne and Alexey Melnikov for general review, to Chris Newman for pointing out an RFC 2231 incompatibility, and to Benjamin Carlyle and Roar Lauritzsen for implementer's feedback.
感谢Martin Duerst和Frank Ellermann帮助我们了解ABNF的详细信息，感谢Graham Klyne和Alexey Melnikov进行全面审查，感谢Chris Newman指出RFC 2231不兼容，感谢Benjamin Carlyle和Roar Lauritzsen提供实施者反馈。
[ISO-8859-1] International Organization for Standardization, "Information technology -- 8-bit single-byte coded graphic character sets -- Part 1: Latin alphabet No. 1", ISO/IEC 8859-1:1998, 1998.
[ISO-8859-1]国际标准化组织，“信息技术——8位单字节编码图形字符集——第1部分：拉丁字母表1”，ISO/IEC 8859-1:1998，1998。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2616]菲尔丁，R.，盖蒂斯，J.，莫卧儿，J.，弗莱斯蒂克，H.，马斯特，L.，利奇，P.，和T.伯纳斯李，“超文本传输协议——HTTP/1.1”，RFC 2616，1999年6月。
[RFC2978] Freed, N. and J. Postel, "IANA Charset Registration Procedures", BCP 19, RFC 2978, October 2000.
[RFC2978]Freed，N.和J.Postel，“IANA字符集注册程序”，BCP 19，RFC 2978，2000年10月。
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC 3629, STD 63, November 2003.
[RFC3629]Yergeau，F.，“UTF-8，ISO 10646的转换格式”，RFC 3629，STD 63，2003年11月。
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", RFC 3986, STD 66, January 2005.
[RFC3986]Berners Lee，T.，Fielding，R.，和L.Masinter，“统一资源标识符（URI）：通用语法”，RFC 3986，STD 66，2005年1月。
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5234]Crocker，D.，Ed.和P.Overell，“语法规范的扩充BNF:ABNF”，STD 68，RFC 5234，2008年1月。
[RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, September 2009.
[RFC5646]Phillips，A.，Ed.和M.Davis，Ed.，“识别语言的标记”，BCP 47，RFC 5646，2009年9月。
[USASCII] American National Standards Institute, "Coded Character Set -- 7-bit American Standard Code for Information Interchange", ANSI X3.4, 1986.
[USASCII]美国国家标准协会，“编码字符集——信息交换用7位美国标准代码”，ANSI X3.41986。
[Err1912] RFC Errata, Errata ID 1912, RFC 2978, <http://www.rfc-editor.org>.
[Err1912]RFC勘误表，勘误表ID 1912，RFC 2978<http://www.rfc-editor.org>.
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996.
[RFC2045]Freed，N.和N.Borenstein，“多用途Internet邮件扩展（MIME）第一部分：Internet邮件正文格式”，RFC 20451996年11月。
[RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996.
[RFC2047]Moore，K.，“MIME（多用途互联网邮件扩展）第三部分：非ASCII文本的消息头扩展”，RFC 2047，1996年11月。
[RFC2231] Freed, N. and K. Moore, "MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations", RFC 2231, November 1997.
[RFC2231]Freed，N.和K.Moore，“MIME参数值和编码字扩展：字符集、语言和连续体”，RFC 22311997年11月。
[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and Languages", BCP 18, RFC 2277, January 1998.
[RFC2277]Alvestrand，H.，“IETF字符集和语言政策”，BCP 18，RFC 2277，1998年1月。
[RFC2388] Masinter, L., "Returning Values from Forms: multipart/ form-data", RFC 2388, August 1998.
[RFC2388]Masinter，L.“从表单返回值：多部分/表单数据”，RFC 23881998年8月。
Author's Address
作者地址
Julian F. Reschke greenbytes GmbH Hafenweg 16 Muenster, NW 48155 Germany
Julian F.Reschke greenbytes GmbH Hafenweg 16 Muenster，西北48155德国
EMail: julian.reschke@greenbytes.de
URI: http://greenbytes.de/tech/webdav/
EMail: julian.reschke@greenbytes.de
URI: http://greenbytes.de/tech/webdav/