Internet Engineering Task Force (IETF) N. Tomkinson
Request for Comments: 8255 N. Borenstein
Category: Standards Track Mimecast, Ltd.
ISSN: 2070-1721 October 2017
Internet Engineering Task Force (IETF) N. Tomkinson
Request for Comments: 8255 N. Borenstein
Category: Standards Track Mimecast, Ltd.
ISSN: 2070-1721 October 2017
Multiple Language Content Type
多语言内容类型
Abstract
摘要
This document defines the 'multipart/multilingual' content type, which is an addition to the Multipurpose Internet Mail Extensions (MIME) standard. This content type makes it possible to send one message that contains multiple language versions of the same information. The translations would be identified by a language tag and selected by the email client based on a user's language settings.
本文档定义了“多部分/多语言”内容类型，它是对多用途Internet邮件扩展（MIME）标准的补充。通过此内容类型，可以发送一条包含同一信息的多个语言版本的消息。翻译将由语言标签标识，并由电子邮件客户端根据用户的语言设置进行选择。
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 7841.
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 7841第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8255.
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https://www.rfc-editor.org/info/rfc8255.
Copyright Notice
版权公告
Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2017 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 (https://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(https://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
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. The Content-Type Header Field . . . . . . . . . . . . . . . . 3
3. The Message Parts . . . . . . . . . . . . . . . . . . . . . . 4
3.1. The Multilingual Preface . . . . . . . . . . . . . . . . 4
3.2. The Language Message Parts . . . . . . . . . . . . . . . 5
3.3. The Language-Independent Message Part . . . . . . . . . . 5
4. Message Part Selection . . . . . . . . . . . . . . . . . . . 6
5. The Content-Language Field . . . . . . . . . . . . . . . . . 6
6. The Content-Translation-Type Field . . . . . . . . . . . . . 7
7. The Subject Field in the Language Message Parts . . . . . . . 8
8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. An Example of a Simple Multiple-Language Email Message . 8
8.2. An Example of a Multiple-Language Email Message with a
Language-Independent Part . . . . . . . . . . . . . . . . 9
8.3. An Example of a Complex Multiple-Language Email Message
with a Language-Independent Part . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
9.1. The 'multipart/multilingual' Media Type . . . . . . . . . 13
9.2. The Content-Translation-Type Field . . . . . . . . . . . 15
9.3. The Content-Translation-Type Header Field Values . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 16
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 18
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. The Content-Type Header Field . . . . . . . . . . . . . . . . 3
3. The Message Parts . . . . . . . . . . . . . . . . . . . . . . 4
3.1. The Multilingual Preface . . . . . . . . . . . . . . . . 4
3.2. The Language Message Parts . . . . . . . . . . . . . . . 5
3.3. The Language-Independent Message Part . . . . . . . . . . 5
4. Message Part Selection . . . . . . . . . . . . . . . . . . . 6
5. The Content-Language Field . . . . . . . . . . . . . . . . . 6
6. The Content-Translation-Type Field . . . . . . . . . . . . . 7
7. The Subject Field in the Language Message Parts . . . . . . . 8
8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. An Example of a Simple Multiple-Language Email Message . 8
8.2. An Example of a Multiple-Language Email Message with a
Language-Independent Part . . . . . . . . . . . . . . . . 9
8.3. An Example of a Complex Multiple-Language Email Message
with a Language-Independent Part . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
9.1. The 'multipart/multilingual' Media Type . . . . . . . . . 13
9.2. The Content-Translation-Type Field . . . . . . . . . . . 15
9.3. The Content-Translation-Type Header Field Values . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 16
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 18
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
Since the invention of email and the rapid spread of the Internet, more and more people have been able to communicate in more and more countries and in more and more languages. But during this time of technological evolution, email has remained a single-language communication tool, whether it is English to English, Spanish to Spanish, or Japanese to Japanese.
自从电子邮件的发明和互联网的迅速普及，越来越多的人能够在越来越多的国家用越来越多的语言进行交流。但在这一技术发展时期，电子邮件仍然是一种单一的语言交流工具，无论是英语对英语，西班牙语对西班牙语，还是日语对日语。
Also during this time, many corporations have established their offices in multicultural cities and have formed departments and teams that span continents, cultures, and languages. Thus, the need to communicate efficiently with little margin for miscommunication has grown significantly.
在此期间，许多公司在多文化城市设立了办事处，并组建了跨大陆、跨文化、跨语言的部门和团队。因此，高效沟通的需求大大增加，几乎没有沟通失误的余地。
This document defines the 'multipart/multilingual' content type, which is an addition to the Multipurpose Internet Mail Extensions (MIME) standard specified in [RFC2045], [RFC2046], [RFC2047],
本文档定义了“多部分/多语言”内容类型，它是[RFC2045]、[RFC2046]、[RFC2047]中指定的多用途Internet邮件扩展（MIME）标准的补充，
[RFC4289], and [RFC6838]. This content type makes it possible to send a single message to a group of people in such a way that all of the recipients can read the email in their preferred language. The methods of translation of the message content are beyond the scope of this document, but the structure of the email itself is defined herein.
[RFC4289]和[RFC6838]。这种内容类型可以向一组人发送一封邮件，这样所有收件人都可以用他们喜欢的语言阅读邮件。邮件内容的翻译方法超出了本文档的范围，但电子邮件本身的结构在本文中有定义。
This document depends on the identification of language in message parts for non-real-time communication. [HUMAN-LANG] is concerned with a similar problem for real-time communication.
本文件取决于非实时通信消息部分的语言标识。[HUMAN-LANG]关注的是一个类似的实时通信问题。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”在所有大写字母出现时（如图所示）应按照BCP 14[RFC2119][RFC8174]所述进行解释。
The 'multipart/multilingual' Media Subtype allows the sending of a message in a number of different languages with the different language versions embedded in the same message. This Media Subtype helps the receiving email client make sense of the message structure.
“多部分/多语言”媒体子类型允许以多种不同语言发送消息，并在同一消息中嵌入不同语言版本。此媒体子类型有助于接收电子邮件的客户端理解消息结构。
The multipart subtype 'multipart/multilingual' has similar semantics to 'multipart/alternative' (as discussed in RFC 2046 [RFC2046]) in that each of the message parts is an alternative version of the same information. The primary difference between 'multipart/multilingual' and 'multipart/alternative' is that when using 'multipart/ multilingual', the message part to select for rendering is chosen based on the values of the Content-Language field and optionally the Content-Translation-Type field instead of the ordering of the parts and the Content-Types.
多部分子类型“multipart/multilingual”与“multipart/alternative”（如RFC 2046[RFC2046]中所述）具有类似的语义，因为每个消息部分都是相同信息的替代版本。“多部分/多语言”和“多部分/备选方案”之间的主要区别在于，当使用“多部分/多语言”时，选择用于呈现的消息部分是基于内容语言字段和可选内容翻译类型字段的值，而不是部分和内容类型的顺序。
The syntax for this multipart subtype conforms to the common syntax for subtypes of multipart given in Section 5.1.1. of RFC 2046 [RFC2046]. An example 'multipart/multilingual' Content-Type header field would look like this:
此多部分子类型的语法符合第5.1.1节中给出的多部分子类型的通用语法。RFC 2046[RFC2046]中的一部分。“多部分/多语言”内容类型标题字段示例如下所示：
Content-Type: multipart/multilingual; boundary=01189998819991197253
Content-Type: multipart/multilingual; boundary=01189998819991197253
A 'multipart/multilingual' message will have a number of message parts: exactly one multilingual preface, one or more language message parts, and zero or one language-independent message part. The details of these are described below.
“多部分/多语言”消息将包含多个消息部分：恰好一个多语言前言、一个或多个语言消息部分，以及零个或一个独立于语言的消息部分。下文介绍了这些措施的细节。
In order for the message to be received and displayed in non-conforming email clients, the message SHOULD contain an explanatory message part that MUST NOT be marked with a Content-Language field and MUST be the first of the message parts. For maximum support in the most basic of non-conforming email clients, it SHOULD have a Content-Type of 'text/plain'. Because non-conforming email clients are expected to treat a message with an unknown multipart type as 'multipart/mixed' (in accordance with Sections 5.1.3 and 5.1.7 of RFC 2046 [RFC2046]), they may show all of the message parts sequentially or as attachments. Including and showing this explanatory part will help the message recipient understand the message structure.
为了在不符合要求的电子邮件客户端中接收和显示消息，消息应包含解释性消息部分，该部分不得标记内容语言字段，并且必须是消息部分的第一部分。为了最大限度地支持最基本的不符合要求的电子邮件客户端，它的内容类型应为“text/plain”。由于不符合要求的电子邮件客户端预期会将未知多部分类型的邮件视为“多部分/混合邮件”（根据RFC 2046[RFC2046]第5.1.3节和第5.1.7节），它们可能会按顺序或作为附件显示所有邮件部分。包含并显示此说明部分将有助于邮件收件人理解邮件结构。
This initial message part SHOULD briefly explain to the recipient that the message contains multiple languages, and the parts may be rendered sequentially or as attachments. This SHOULD be presented in the same languages that are provided in the subsequent language message parts.
此初始邮件部分应向收件人简要说明邮件包含多种语言，这些部分可以按顺序呈现或作为附件呈现。这应以后续语言消息部分中提供的相同语言呈现。
As this explanatory section is likely to contain languages using scripts that require non-US-ASCII characters, it is RECOMMENDED that a UTF-8 charset be used for this message part. See RFC 3629 [RFC3629] for details of UTF-8.
由于本说明部分可能包含使用需要非US ASCII字符的脚本的语言，因此建议在此消息部分使用UTF-8字符集。有关UTF-8的详细信息，请参见RFC 3629[RFC3629]。
Whilst this section of the message is useful for backward compatibility, it will normally only be shown when rendered by a non-conforming email client. This is because conforming email clients SHOULD only show the single language message part identified by the user's preferred language and the language message part's Content-Language.
虽然此部分消息对于向后兼容性很有用，但通常仅在由不一致的电子邮件客户端呈现时才会显示。这是因为一致性电子邮件客户端应仅显示由用户首选语言和语言消息部分内容语言标识的单一语言消息部分。
For the correct display of the multilingual preface in a non-conforming email client, the sender MAY use the Content-Disposition field with a value of 'inline' in conformance with RFC 2183 [RFC2183] (which defines the Content-Disposition field). If provided, this SHOULD be placed at the 'multipart/multilingual' level and in the multilingual preface. This makes it clear to a non-conforming email client that the multilingual preface should be displayed immediately
为了在不符合要求的电子邮件客户端中正确显示多语言前言，发件人可以使用值为“inline”的内容处置字段，以符合RFC 2183[RFC2183]（定义内容处置字段）的要求。如果提供，应将其置于“多部分/多语言”级别和多语言前言中。这向不符合要求的电子邮件客户端表明，应立即显示多语言前言
to the recipient, followed by any subsequent parts marked as 'inline'.
收件人，然后是标记为“内联”的任何后续部分。
For examples of a multilingual preface, see Section 8.
有关多语言前言的示例，请参见第8节。
The language message parts are typically translations of the same message content. These message parts SHOULD be ordered so that the first part after the multilingual preface is in the language believed to be the most likely to be recognized by the recipient; this will constitute the default part when language negotiation fails and there is no language-independent part. All of the language message parts MUST have a Content-Language field and a Content-Type field; they MAY have a Content-Translation-Type field.
语言消息部分通常是相同消息内容的翻译。这些信息部分应按顺序排列，以便多语种前言后的第一部分使用收件人认为最可能识别的语言；当语言协商失败且没有语言独立部分时，这将构成默认部分。所有语言消息部分必须具有内容语言字段和内容类型字段；它们可能有一个内容翻译类型字段。
The Content-Type for each individual language message part SHOULD be 'message/rfc822' to provide good support with non-conforming email clients. However, an implementation MAY use 'message/global' as support for 'message/global' becomes more commonplace. (See RFC 6532 [RFC6532] for details of 'message/global'.) Each language message part should have a Subject field in the appropriate language for that language part. If there is a From field present, its value MUST include the same email address as the top-level From header field, although the display name MAY be a localized version. If there is a mismatch of sender email address, the top-level From header field value SHOULD be used to show to the recipient.
每个单独语言消息部分的内容类型应为“message/rfc822”，以便为不符合要求的电子邮件客户端提供良好的支持。然而，一个实现可能会使用“消息/全局”，因为对“消息/全局”的支持变得越来越普遍。（有关“消息/全局”的详细信息，请参见RFC 6532[RFC6532]）每个语言消息部分都应具有该语言部分相应语言的主题字段。如果存在“发件人”字段，则其值必须包含与顶级“发件人”标题字段相同的电子邮件地址，尽管显示名称可能是本地化版本。如果发件人电子邮件地址不匹配，则应使用顶级发件人标题字段值向收件人显示。
If there is language-independent content for the recipient to see if they have a preferred language other than one of those specified in the language message parts, and the default language message part is unlikely to be understood, another part MAY be provided. This part could typically include one or more language-independent graphics. When this part is present, it MUST be the last part and MUST have a Content-Language field with a value of "zxx" (as described in BCP 47 [RFC5646]). The part SHOULD have a Content-Type of 'message/rfc822' or 'message/global' (to match the language message parts).
如果存在独立于语言的内容供接收者查看其是否具有语言消息部分中指定的语言以外的首选语言，并且不太可能理解默认语言消息部分，则可以提供另一部分。此部分通常可以包括一个或多个独立于语言的图形。当存在此部分时，它必须是最后一部分，并且必须有一个值为“zxx”的内容语言字段（如BCP 47[RFC5646]中所述）。该部分的内容类型应为“message/rfc822”或“message/global”（以匹配语言消息部分）。
The logic for selecting the message part to render and present to the recipient is summarized in the next few paragraphs.
下面几段将总结选择要呈现并呈现给收件人的消息部分的逻辑。
If the email client does not understand 'multipart/multilingual', then it will treat the message as if it was 'multipart/mixed' and render message parts accordingly (in accordance with Sections 5.1.3 and 5.1.7 of RFC 2046 [RFC2046]).
如果电子邮件客户端不理解“多部分/多语言”，则会将邮件视为“多部分/混合”，并相应地呈现邮件部分（根据RFC 2046[RFC2046]第5.1.3节和第5.1.7节）。
If the email client does understand 'multipart/multilingual', then it SHOULD ignore the multilingual preface and select the best match for the user's preferred language from the language message parts available. Also, the user may prefer to see the original message content in their second language over a machine translation in their first language. The Content-Translation-Type field value can be used for further selection based on this preference. The selection of the language part may be implemented in a variety of ways, although the matching schemes detailed in RFC 4647 [RFC4647] are RECOMMENDED as a starting point for an implementation. The goal is to render the most appropriate translation for the user.
如果电子邮件客户端确实理解“多部分/多语言”，则应忽略多语言前言，并从可用的语言消息部分中选择与用户首选语言最匹配的语言。此外，用户可能更愿意看到第二语言的原始消息内容，而不是第一语言的机器翻译。“内容翻译类型”字段值可用于基于此首选项的进一步选择。语言部分的选择可以以多种方式实现，尽管建议将RFC 4647[RFC4647]中详述的匹配方案作为实现的起点。目标是为用户呈现最合适的翻译。
If there is no match for the user's preferred language or there is no preferred language information available, the email client SHOULD select the language-independent part (if one exists) or the first language part directly after the multilingual preface if a language-independent part does not exist.
如果与用户的首选语言不匹配或没有可用的首选语言信息，则电子邮件客户端应选择与语言无关的部分（如果存在），或直接在多语言前言后选择第一语言部分（如果不存在与语言无关的部分）。
If there is no translation type preference information available, the values of the Content-Translation-Type field may be ignored.
如果没有可用的翻译类型首选项信息，则可以忽略“内容翻译类型”字段的值。
Additionally, interactive implementations MAY offer the user a choice from among the available languages or the option to see them all.
此外，交互实现可以为用户提供从可用语言中进行选择或查看所有语言的选项。
The Content-Language field in the individual language message parts is used to identify the language in which the message part is written. Based on the value of this field, a conforming email client can determine which message part to display (given the user's language settings).
各个语言消息部分中的内容语言字段用于标识编写消息部分的语言。根据此字段的值，符合条件的电子邮件客户端可以确定要显示的消息部分（给定用户的语言设置）。
The Content-Language MUST comply with RFC 3282 [RFC3282] (which defines the Content-Language field) and BCP 47 [RFC5646] (which defines the structure and semantics for the language tag values).
内容语言必须符合RFC 3282[RFC3282]（定义内容语言字段）和BCP 47[RFC5646]（定义语言标记值的结构和语义）。
Examples of this field could look like the following:
此字段的示例如下所示：
Content-Language: en-GB
内容语言：en GB
Content-Language: de
内容语言：de
Content-Language: es-MX, fr
内容语言：es MX，fr
Content-Language: sr-Cyrl
内容语言：sr Cyrl
The Content-Translation-Type field can be used in the individual language message parts to identify the type of translation. Based on the value of this field and the user's preferences, a conforming email client can determine which message part to display.
“内容翻译类型”字段可用于各个语言消息部分，以标识翻译类型。根据此字段的值和用户的偏好，一致性电子邮件客户端可以确定要显示的消息部分。
This field can have one of three possible values: 'original', 'human', or 'automated' (although other values may be added in the future). A value of 'original' is given in the language message part that is in the original language. A value of 'human' is used when a language message part is translated by a human translator or a human has checked and corrected an automated translation. A value of 'automated' is used when a language message part has been translated by an electronic agent without proofreading or subsequent correction. New values of the Content-Translation-Type header field ("translTypeExt" in the ABNF) are added according to the procedure specified in Section 9.3.
此字段可以有三个可能的值之一：“原始”、“人工”或“自动”（尽管将来可能会添加其他值）。原始语言的语言消息部分中给出了“original”的值。当人工翻译人员翻译语言消息部分或人工检查并更正自动翻译时，使用“human”值。当电子代理翻译了语言消息部分而未进行校对或后续更正时，使用“自动”值。根据第9.3节规定的程序，添加内容翻译类型标题字段的新值（“ABNF中的translTypeExt”）。
Examples of this field include:
该领域的例子包括：
Content-Translation-Type: original
内容翻译类型：原文
Content-Translation-Type: human
内容翻译类型：人类
The syntax of the Content-Translation-Type field in ABNF [RFC5234] is:
ABNF[RFC5234]中内容翻译类型字段的语法为：
Content-Translation-Type = [FWS] translationtype
Content-Translation-Type = [FWS] translationtype
FWS = <Defined in RFC 5322>
translationtype = "original" / "human" / "automated" /
translTypeExt
translTypeExt = 1*atext
atext = <Defined in RFC 5322>
FWS = <Defined in RFC 5322>
translationtype = "original" / "human" / "automated" /
translTypeExt
translTypeExt = 1*atext
atext = <Defined in RFC 5322>
This references RFC 5322 [RFC5322] for the predefined rules 'folding white space (FWS)' and 'atext'.
对于预定义规则“折叠空白（FWS）”和“atext”，参考RFC 5322[RFC5322]。
On receipt of the message, conforming email clients will need to render the subject in the correct language for the recipient. To enable this, the Subject field SHOULD be provided in each language message part. The value for this field should be a translation of the email subject.
收到邮件后，符合要求的电子邮件客户端需要为收件人提供正确的主题语言。要启用此功能，应在每个语言消息部分中提供主题字段。此字段的值应为电子邮件主题的翻译。
US-ASCII and 'encoded-word' examples of this field include:
此字段的US-ASCII和“编码字”示例包括：
Subject: A really simple email subject
主题：一个非常简单的电子邮件主题
Subject: =?UTF-8?Q?Un_asunto_de_correo_electr=C3=b3nico_
realmente_sencillo?=
Subject: =?UTF-8?Q?Un_asunto_de_correo_electr=C3=b3nico_
realmente_sencillo?=
See RFC 2047 [RFC2047] for the specification of 'encoded-word'.
有关“编码字”的规范，请参见RFC 2047[RFC2047]。
The subject to be presented to the recipient SHOULD be selected from the message part identified during the message part selection stage. If no Subject field is found, the top-level Subject header field value should be used.
应从消息部分选择阶段确定的消息部分中选择要呈现给收件人的主题。如果未找到主题字段，则应使用顶级主题标题字段值。
Below is a minimal example of a multiple-language email message. It has the multilingual preface and two language message parts.
下面是一个简单的多语言电子邮件示例。它有多语种的前言和两个语种的信息部分。
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 21:28:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 21:28:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
This is a message in multiple languages. It says the same thing in each language. If you can read it in one language, you can ignore the other translations. The other translations may be presented as attachments or grouped together.
这是一条多语言的信息。每种语言都说同样的话。如果你能用一种语言阅读，你可以忽略其他的翻译。其他翻译可以作为附件呈现或组合在一起。
Este es un mensaje en varios idiomas. Dice lo mismo en cada idioma. Si puede leerlo en un idioma, puede ignorar las otras traducciones. Las otras traducciones pueden presentarse como archivos adjuntos o agrupados.
这是一种习惯用法。把米斯莫切成方块。这是一种习惯，是一种传统。拉斯奥特拉斯普伊登是阿格鲁帕多斯的副官。
--01189998819991197253 Content-Type: message/rfc822 Content-Language: en-GB Content-Translation-Type: original Content-Disposition: inline
--01189998819991197253内容类型：消息/rfc822内容语言：en GB内容翻译类型：原始内容处置：内联
Subject: Example of a message in Spanish and English
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: Example of a message in Spanish and English
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Hello, this message content is provided in your language.
您好，此邮件内容以您的语言提供。
--01189998819991197253 Content-Type: message/rfc822 Content-Language: es Content-Translation-Type: human Content-Disposition: inline
--01189998819991197253内容类型：消息/rfc822内容语言：es内容翻译类型：人类内容处置：内联
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Hola, el contenido de este mensaje esta disponible en su idioma.
您好，我们的辩论是有争议的。
--01189998819991197253--
--01189998819991197253--
8.2. An Example of a Multiple-Language Email Message with a Language-Independent Part
8.2. 具有独立于语言的部分的多语言电子邮件示例
Below is an example of a multiple-language email message that has the multilingual preface followed by two language message parts and then a language-independent png image.
下面是一个多语言电子邮件消息的示例，它有多语言前言，后面是两个语言消息部分，然后是一个独立于语言的png图像。
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 21:08:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 21:08:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
This is a message in multiple languages. It says the same thing in each language. If you can read it in one language, you can ignore the other translations. The other translations may be presented as attachments or grouped together.
这是一条多语言的信息。每种语言都说同样的话。如果你能用一种语言阅读，你可以忽略其他的翻译。其他翻译可以作为附件呈现或组合在一起。
Este es un mensaje en varios idiomas. Dice lo mismo en cada idioma. Si puede leerlo en un idioma, puede ignorar las otras traducciones. Las otras traducciones pueden presentarse como archivos adjuntos o agrupados.
这是一种习惯用法。把米斯莫切成方块。这是一种习惯，是一种传统。拉斯奥特拉斯普伊登是阿格鲁帕多斯的副官。
--01189998819991197253 Content-Type: message/rfc822 Content-Language: en Content-Translation-Type: original Content-Disposition: inline
--01189998819991197253内容类型：消息/rfc822内容语言：en内容翻译类型：原始内容处置：内联
Subject: Example of a message in Spanish and English
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: Example of a message in Spanish and English
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Hello, this message content is provided in your language.
您好，此邮件内容以您的语言提供。
--01189998819991197253 Content-Type: message/rfc822 Content-Language: es-ES Content-Translation-Type: human Content-Disposition: inline
--01189998819991197253内容类型：消息/rfc822内容语言：es es内容翻译类型：人类内容处置：内联
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Hola, el contenido de este mensaje esta disponible en su idioma.
您好，我们的辩论是有争议的。
--01189998819991197253
Content-Type: message/rfc822; name="Icon"
Content-Language: zxx
Content-Disposition: inline
--01189998819991197253
Content-Type: message/rfc822; name="Icon"
Content-Language: zxx
Content-Disposition: inline
Content-Type: image/png; name="icon.png"
Content-Transfer-Encoding: base64
Content-Type: image/png; name="icon.png"
Content-Transfer-Encoding: base64
iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAKQ2lDQ1BJQ0MgUHJvZmlsZ QAASA2dlndUU1... shortened for brevity ...7yxfd1SNsEy+OXr76qr 997zF2hvZYeDEP5ftGV6Xzx2o9MAAAAASUVORK5CYII=
IVBORW0KGGOAAAANSUHEUGAAAAAAAAAWCAYAAABXAVMHAAAKQ2LDQ1BJQ0MGUHJVZMLSZ QAASA2dlndUU1。。。为简洁而缩短…7YXFD1NSEY+OXr76qr 997ZF2HVZYEDEP5FTGV6XZX2O9MAAAASUVORK5CYII=
--01189998819991197253--
--01189998819991197253--
8.3. An Example of a Complex Multiple-Language Email Message with a Language-Independent Part
8.3. 具有语言独立部分的复杂多语言电子邮件示例
Below is an example of a more complex multiple-language email message. It has the multilingual preface and two language message parts and then a language-independent png image. The language message parts have 'multipart/alternative' contents and would therefore require further processing to determine the content to display.
下面是一个更复杂的多语言电子邮件消息的示例。它有多语言前言和两个语言消息部分，然后是一个独立于语言的png图像。语言消息部分具有“多部分/备选”内容，因此需要进一步处理以确定要显示的内容。
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 20:55:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
From: Nik@example.com
To: Nathaniel@example.com
Subject: Example of a message in Spanish and English
Date: Thu, 7 Apr 2017 20:55:00 +0100
MIME-Version: 1.0
Content-Type: multipart/multilingual;
boundary="01189998819991197253"
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
--01189998819991197253
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
This is a message in multiple languages. It says the same thing in each language. If you can read it in one language, you can ignore the other translations. The other translations may be presented as attachments or grouped together.
这是一条多语言的信息。每种语言都说同样的话。如果你能用一种语言阅读，你可以忽略其他的翻译。其他翻译可以作为附件呈现或组合在一起。
Este es un mensaje en varios idiomas. Dice lo mismo en cada idioma. Si puede leerlo en un idioma, puede ignorar las otras traducciones. Las otras traducciones pueden presentarse como archivos adjuntos o agrupados.
这是一种习惯用法。把米斯莫切成方块。这是一种习惯，是一种传统。拉斯奥特拉斯普伊登是阿格鲁帕多斯的副官。
--01189998819991197253 Content-Type: message/rfc822 Content-Language: en Content-Translation-Type: original Content-Disposition: inline
--01189998819991197253内容类型：消息/rfc822内容语言：en内容翻译类型：原始内容处置：内联
Subject: Example of a message in Spanish and English
Content-Type: multipart/alternative;
boundary="72530118999911999881"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: Example of a message in Spanish and English
Content-Type: multipart/alternative;
boundary="72530118999911999881"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
--72530118999911999881
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
--72530118999911999881
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Hello, this message content is provided in your language.
您好，此邮件内容以您的语言提供。
--72530118999911999881
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
--72530118999911999881
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<html><body>Hello, this message content is <b>provided</b> in
<i>your</i> language.</body></html>
<html><body>Hello, this message content is <b>provided</b> in
<i>your</i> language.</body></html>
--72530118999911999881-- --01189998819991197253 Content-Type: message/rfc822 Content-Language: es Content-Translation-Type: human Content-Disposition: inline
--72530118999911999881--01189998819991197253内容类型：消息/rfc822内容语言：es内容翻译类型：人类内容处置：内联
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: multipart/alternative;
boundary="53011899989991197281"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Subject: =?UTF-8?Q?Ejemplo_pr=C3=A1ctico_de_mensaje_?=
=?UTF-8?Q?en_espa=C3=B1ol_e_ingl=C3=A9s?=
Content-Type: multipart/alternative;
boundary="53011899989991197281"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
--53011899989991197281
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
--53011899989991197281
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Hola, el contenido de este mensaje esta disponible en su idioma.
您好，我们的辩论是有争议的。
--53011899989991197281
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
--53011899989991197281
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<html><body>Hola, el contenido de este <b>mensaje</b> <i>esta</i>
disponible en su idioma.</body></html>
<html><body>Hola, el contenido de este <b>mensaje</b> <i>esta</i>
disponible en su idioma.</body></html>
--53011899989991197281-- --01189998819991197253 Content-Type: message/rfc822; name="Icon" Content-Language: zxx Content-Disposition: inline
--53011899989991197281--01189998819991197253内容类型：message/rfc822；name=“Icon”内容语言：zxx内容配置：内联
Content-Type: multipart/mixed;
boundary="99911972530118999881"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="99911972530118999881"; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
--99911972530118999881
--99911972530118999881
Content-Type: image/png; name="icon.png"
Content-Disposition: inline
Content-Transfer-Encoding: base64
Content-Type: image/png; name="icon.png"
Content-Disposition: inline
Content-Transfer-Encoding: base64
iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAKQ2lDQ1BJQ0MgUHJvZmlsZ QAASA2dlndUU1... shortened for brevity ...7yxfd1SNsEy+OXr76qr 997zF2hvZYeDEP5ftGV6Xzx2o9MAAAAASUVORK5CYII=
IVBORW0KGGOAAAANSUHEUGAAAAAAAAAWCAYAAABXAVMHAAAKQ2LDQ1BJQ0MGUHJVZMLSZ QAASA2dlndUU1。。。为简洁而缩短…7YXFD1NSEY+OXr76qr 997ZF2HVZYEDEP5FTGV6XZX2O9MAAAASUVORK5CYII=
--99911972530118999881-- --01189998819991197253--
--99911972530118999881-- --01189998819991197253--
The 'multipart/multilingual' Media Type has been registered with IANA. This is the registration template based on the template specified in [RFC6838]:
“多部分/多语言”媒体类型已向IANA注册。这是基于[RFC6838]中指定的模板的注册模板：
Media Type name: multipart
媒体类型名称：多部分
Media subtype name: multilingual
媒体子类型名称：多语言
Required parameters: boundary (defined in RFC 2046)
所需参数：边界（在RFC 2046中定义）
Optional parameters: N/A
可选参数：不适用
Encoding considerations: There are no encoding considerations for this multipart other than that of the embedded body parts. The embedded body parts (typically one 'text/plain' plus one or more 'message/*') may contain 7-bit, 8-bit, or binary encodings.
编码注意事项：除了嵌入式身体部位的编码注意事项外，此多部件没有编码注意事项。嵌入的身体部位（通常是一个“文本/普通”加上一个或多个“消息/*”）可能包含7位、8位或二进制编码。
Security considerations: See the Security Considerations section in RFC 8255
安全注意事项：请参阅RFC 8255中的安全注意事项部分
Interoperability considerations: Existing systems that do not treat unknown multipart subtypes as 'multipart/mixed' may not correctly render a 'multipart/multilingual' type. These systems would also be non-compliant with MIME.
互操作性注意事项：不将未知多部分子类型视为“多部分/混合”的现有系统可能无法正确呈现“多部分/多语言”类型。这些系统也不符合MIME。
Published specification: RFC 8255
已发布规范：RFC 8255
Applications that use this media type: Mail Transfer Agents, Mail User Agents, spam detection, virus detection modules, and message authentication modules.
使用此媒体类型的应用程序：邮件传输代理、邮件用户代理、垃圾邮件检测、病毒检测模块和邮件身份验证模块。
Fragment identifier considerations: N/A
片段标识符注意事项：不适用
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): N/A
Macintosh file type code(s): N/A
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): N/A
Macintosh file type code(s): N/A
Person & email address to contact for further information: Nik Tomkinson rfc.nik.tomkinson@gmail.com
联系人和电子邮件地址，以获取更多信息：Nik Tomkinson rfc.Nik。tomkinson@gmail.com
Nathaniel Borenstein nsb@mimecast.com
纳撒尼尔·博伦斯坦nsb@mimecast.com
Intended usage: COMMON
预期用途：普通
Restrictions on usage: N/A
使用限制：不适用
Author/Change controller: IETF
作者/变更控制员：IETF
The Content-Translation-Type field has been added to the IANA "Permanent Message Header Field Names" registry. That entry references this document. This registration template is below:
内容翻译类型字段已添加到IANA“永久消息标题字段名称”注册表中。该条目引用此文档。此注册模板如下所示：
Header field name: Content-Translation-Type
标题字段名称：内容翻译类型
Applicable protocol: MIME
适用协议：MIME
Status: standard
状态：标准
Author/Change controller: IETF
作者/变更控制员：IETF
Specification document(s): RFC 8255
规范文件：RFC 8255
Related information: none
相关信息：无
IANA has created a new registry titled "Content-Translation-Type Header Field Values". New values must be registered using the "Specification Required" [RFC8126] IANA registration procedure. Registrations must include a translation type value, a short description, and a reference to the specification.
IANA创建了一个名为“内容转换类型标题字段值”的新注册表。必须使用“所需规范”[RFC8126]IANA注册程序注册新值。注册必须包括翻译类型值、简短描述和对规范的引用。
This document also registers three initial values specified below.
本文件还记录了以下指定的三个初始值。
Value: original Description: Content in the original language Reference: RFC 8255
值：原始描述：原始语言内容参考：RFC 8255
Value: human Description: Content that has been translated by a human translator or a human has checked and corrected an automated translation Reference: RFC 8255
值：人工描述：人工翻译或人工检查并更正自动翻译参考的内容：RFC 8255
Value: automated Description: Content that has been translated by an electronic agent without proofreading or subsequent correction Reference: RFC 8255
价值：自动描述：由电子代理翻译而未经校对或后续更正的内容参考：RFC 8255
Whilst it is intended that each language message part is a direct translation of the original message, this may not always be the case; these parts could contain undesirable content. Therefore, there is a possible risk that undesirable text or images could be shown to the recipient if the message is passed through a spam filter that does not check all of the message parts. The risk should be minimal due to the fact that an unknown multipart subtype should be treated as 'multipart/mixed'; thus, each message part should be subsequently scanned.
虽然每个语言信息部分都是原始信息的直接翻译，但情况并非总是如此；这些部分可能包含不需要的内容。因此，如果邮件通过未检查所有邮件部分的垃圾邮件过滤器，则可能存在向收件人显示不需要的文本或图像的风险。由于未知的多部分亚型应被视为“多部分/混合”，因此风险应最小；因此，应随后扫描每个消息部分。
If the email contains undesirable content in a language that the recipient cannot understand and this unknown content is assumed to be a direct translation of the content that the recipient can understand, the recipient may unintentionally forward undesirable content to a recipient that can understand it. To mitigate this risk, an interactive implementation may allow the recipient to see all of the translations for comparison.
如果电子邮件包含收件人无法理解的语言的不需要的内容，并且该未知内容被认为是收件人能够理解的内容的直接翻译，则收件人可能会无意中将不需要的内容转发给能够理解它的收件人。为了降低这种风险，交互式实现可能允许接收者查看所有翻译以进行比较。
Because the language message parts have a Content-Type of 'message/ rfc822' or 'message/global', they might contain From fields that could have different values from that of the top-level From field, and they may not reflect the actual sender. The inconsistent From field values might get shown to the recipient in a non-conforming email client and may mislead the recipient into thinking that the email came from someone other than the real sender.
由于语言消息部分的内容类型为“message/rfc822”或“message/global”，因此它们可能包含的From字段的值与顶级From字段的值不同，并且可能无法反映实际发件人。不一致的“发件人”字段值可能会在不一致的电子邮件客户端中显示给收件人，并可能误导收件人认为电子邮件来自真实发件人以外的其他人。
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996, <https://www.rfc-editor.org/info/rfc2045>.
[RFC2045]Freed，N.和N.Borenstein，“多用途互联网邮件扩展（MIME）第一部分：互联网邮件正文格式”，RFC 2045，DOI 10.17487/RFC20451996年11月<https://www.rfc-editor.org/info/rfc2045>.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, DOI 10.17487/RFC2046, November 1996, <https://www.rfc-editor.org/info/rfc2046>.
[RFC2046]Freed，N.和N.Borenstein，“多用途互联网邮件扩展（MIME）第二部分：媒体类型”，RFC 2046，DOI 10.17487/RFC2046，1996年11月<https://www.rfc-editor.org/info/rfc2046>.
[RFC2047] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, DOI 10.17487/RFC2047, November 1996, <https://www.rfc-editor.org/info/rfc2047>.
[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，DOI 10.17487/RFC2047，1996年11月<https://www.rfc-editor.org/info/rfc2047>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<https://www.rfc-editor.org/info/rfc2119>.
[RFC2183] Troost, R., Dorner, S., and K. Moore, Ed., "Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field", RFC 2183, DOI 10.17487/RFC2183, August 1997, <https://www.rfc-editor.org/info/rfc2183>.
[RFC2183]Troost，R.，Dorner，S.，和K.Moore，Ed.，“在互联网消息中传达呈现信息：内容处置标题字段”，RFC 2183，DOI 10.17487/RFC2183，1997年8月<https://www.rfc-editor.org/info/rfc2183>.
[RFC3282] Alvestrand, H., "Content Language Headers", RFC 3282, DOI 10.17487/RFC3282, May 2002, <https://www.rfc-editor.org/info/rfc3282>.
[RFC3282]Alvestrand，H.，“内容语言标题”，RFC 3282，DOI 10.17487/RFC3282，2002年5月<https://www.rfc-editor.org/info/rfc3282>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November 2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC3629]Yergeau，F.，“UTF-8，ISO 10646的转换格式”，STD 63，RFC 3629，DOI 10.17487/RFC3629，2003年11月<https://www.rfc-editor.org/info/rfc3629>.
[RFC4289] Freed, N. and J. Klensin, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", BCP 13, RFC 4289, DOI 10.17487/RFC4289, December 2005, <https://www.rfc-editor.org/info/rfc4289>.
[RFC4289]Freed，N.和J.Klensin，“多用途互联网邮件扩展（MIME）第四部分：注册程序”，BCP 13，RFC 4289，DOI 10.17487/RFC4289，2005年12月<https://www.rfc-editor.org/info/rfc4289>.
[RFC4647] Phillips, A. and M. Davis, "Matching of Language Tags", BCP 47, RFC 4647, DOI 10.17487/RFC4647, September 2006, <https://www.rfc-editor.org/info/rfc4647>.
[RFC4647]Phillips，A.和M.Davis，“语言标记的匹配”，BCP 47，RFC 4647，DOI 10.17487/RFC4647，2006年9月<https://www.rfc-editor.org/info/rfc4647>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/RFC5234, January 2008, <https://www.rfc-editor.org/info/rfc5234>.
[RFC5234]Crocker，D.，Ed.和P.Overell，“语法规范的扩充BNF:ABNF”，STD 68，RFC 5234，DOI 10.17487/RFC5234，2008年1月<https://www.rfc-editor.org/info/rfc5234>.
[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322, DOI 10.17487/RFC5322, October 2008, <https://www.rfc-editor.org/info/rfc5322>.
[RFC5322]Resnick，P.，Ed.，“互联网信息格式”，RFC 5322，DOI 10.17487/RFC5322，2008年10月<https://www.rfc-editor.org/info/rfc5322>.
[RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646, September 2009, <https://www.rfc-editor.org/info/rfc5646>.
[RFC5646]Phillips，A.，Ed.和M.Davis，Ed.，“识别语言的标签”，BCP 47，RFC 5646，DOI 10.17487/RFC5646，2009年9月<https://www.rfc-editor.org/info/rfc5646>.
[RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized Email Headers", RFC 6532, DOI 10.17487/RFC6532, February 2012, <https://www.rfc-editor.org/info/rfc6532>.
[RFC6532]Yang，A.，Steele，S.，和N.Freed，“国际化电子邮件头”，RFC 6532，DOI 10.17487/RFC6532，2012年2月<https://www.rfc-editor.org/info/rfc6532>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type Specifications and Registration Procedures", BCP 13, RFC 6838, DOI 10.17487/RFC6838, January 2013, <https://www.rfc-editor.org/info/rfc6838>.
[RFC6838]Freed，N.，Klensin，J.和T.Hansen，“介质类型规范和注册程序”，BCP 13，RFC 6838，DOI 10.17487/RFC6838，2013年1月<https://www.rfc-editor.org/info/rfc6838>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, <https://www.rfc-editor.org/info/rfc8126>.
[RFC8126]Cotton，M.，Leiba，B.，和T.Narten，“在RFC中编写IANA考虑事项部分的指南”，BCP 26，RFC 8126，DOI 10.17487/RFC8126，2017年6月<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8174]Leiba，B.，“RFC 2119关键词中大写与小写的歧义”，BCP 14，RFC 8174，DOI 10.17487/RFC8174，2017年5月<https://www.rfc-editor.org/info/rfc8174>.
[HUMAN-LANG] Gellens, R., "Negotiating Human Language in Real-Time Communications", Work in Progress, draft-ietf-slim-negotiating-human-language-13, July 2017.
[HUMAN-LANG]Gellens，R.，“在实时通信中协商人类语言”，正在进行的工作，草稿-ietf-slim-CONTATING-HUMAN-Language-132017年7月。
Acknowledgements
致谢
The authors are grateful for the helpful input received from many people but would especially like to acknowledge the help of Harald Alvestrand, Stephane Bortzmeyer, Eric Burger, Ben Campbell, Mark Davis, Doug Ewell, Ned Freed, Randall Gellens, Gunnar Hellstrom, Mirja Kuehlewind, Barry Leiba, Sean Leonard, John Levine, Alexey Melnikov, Addison Phillips, Julian Reschke, Pete Resnick, Adam Roach, Brian Rosen, Fiona Tomkinson, Simon Tyler, and Daniel Vargha.
作者感谢许多人提供的有用信息，但特别要感谢Harald Alvestrand、Stephane Bortzmeyer、Eric Burger、Ben Campbell、Mark Davis、Doug Ewell、Ned Freed、Randall Gellens、Gunnar Hellstrom、Mirja Kuehlewind、Barry Leiba、Sean Leonard、John Levine、Alexey Melnikov、，Addison Phillips，Julian Reschke，Pete Resnick，Adam Roach，Brian Rosen，Fiona Tomkinson，Simon Tyler，和Simon Tyler。
The authors would also like to thank Fernando Alvaro and Luis de Pablo for their work on the Spanish translations.
作者还要感谢费尔南多·阿尔瓦罗和路易斯·德·巴勃罗在西班牙语翻译方面所做的工作。
Authors' Addresses
作者地址
Nik Tomkinson Mimecast, Ltd. CityPoint, One Ropemaker Street London EC2Y 9AW United Kingdom
Nik Tomkinson Mimecast有限公司位于英国伦敦Ropemaker街一号CityPoint，邮编EC2Y 9AW
Email: rfc.nik.tomkinson@gmail.com
Email: rfc.nik.tomkinson@gmail.com
Nathaniel Borenstein Mimecast, Ltd. 480 Pleasant Street Watertown, MA 02472 United States of America
Nathaniel Borenstein Mimecast有限公司，马萨诸塞州沃特敦怡人街480号，美国02472
Email: nsb@mimecast.com
Email: nsb@mimecast.com