Network Working Group D. Crocker Internet-Draft Brandenburg InternetWorking Intended status: Informational R. Signes Expires: April 19, 2021 Semiotic Systems October 16, 2020 React: Indicating Summary Reaction to a Message draft-crocker-inreply-react-02 Abstract The popularity of social media has led to user comfort with easily signaling basic reactions to an author's posting, such as with a 'thumbs up' or 'smiley' graphic indication. This specification permits a similar facility for Internet Mail. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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Crocker & Signes Expires April 19, 2021 [Page 1] Internet-Draft react October 2020 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. In-Reply-React . . . . . . . . . . . . . . . . . . . . . . . 3 3. Usability Considerations . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . 5 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction The popularity of social media has led to user comfort with easily signaling summary reactions to an author's posting, by marking basic emoji graphics, such as with a 'thumbs up', 'heart', or 'smiley' indication. Sometimes the permitted repertoire is constrained to a small set and sometimes a more extensive range of indicators is supported. This specification defines a similar facility for Internet Mail. While it is already possible to include symbols and graphics as part of an email reply's content, there has not been an established means of signalling the semantic substance that such data are to be taken as a summary 'reaction' to the original message. That is, a mechanism to identify symbols as specifically providing a summary reaction to the cited message, rather than merely being part of the free text in the body of a response. Such a structured use of the symbol(s) allows recipient MUAs to correlate this reaction to the original message and possibly to display the information distinctively. This facility defines a header field, to be used in junction with the In-Reply-To header field, to link one or more emojis as a summary reaction to a previous message. Unless provided here, terminology, architecture and specification used in this document are incorporated from [Mail-Arch], [Mail-Fmt] and [ABNF]. The ABNF rule Emoji-Seq is inherited from [Emoji-Seq]. Discussion of this specification should take place on the ietf- 822@ietf.org mailing list. Crocker & Signes Expires April 19, 2021 [Page 2] Internet-Draft react October 2020 2. In-Reply-React A message sent as a reply MAY indicate the responder's summary reaction to the original message by including an In-Reply-React header field: The [ABNF] for the header field is: in-reply-react = "In-Reply-React:" emoji *(lwsp emoji) CRLF emoji = emoji_sequence emoji_sequence = { defined in [Emoji-Seq] } base-emojis = thumbs-up / thumbs-down / grinning-face / frowning-face / crying-face thumbs-up = {U+1F44D} thumbs-down = {U+1F44E} grinning-face = {U+1F600} frowning-face = {U+2639} crying-face = {U+1F622} The rule emoji_sequence is inherited from [Emoji-Seq]. It permits one or more bytes to form a single presentation image. The emoji(s) express a recipient's summary reaction to the specific message referenced by the accompanying In-Reply-To header field. [Mail-Fmt]. Fully interoperable email uses 7-bit ASCII, although some email handling paths directly support 8-bit data. Emoji characters are drawn from the space outside of 7-bit ASCII. For email handling paths that are 8-bit clean, the an emoji character does not need special encoding. If the path from author to recipients is not known to be 8-bit clean, The emoji character SHOULD be encoded using [MIME-Enc]. Reference to unallocated code points SHOULD NOT be treated as an error; associated bytes SHOULD be processed using the system default method for denoting an unallocated or undisplayable code point. For recipient MUAs that do not support this mechanism, the header field might not be displayed to the recipient. To ensure that the reaction is presented to the recipient, the responding MUA MAY automatically include a second copy of the header field in the message body. This might be as the first line of the body or as the first mime-part. [MIME] By making the text be the full header field, Crocker & Signes Expires April 19, 2021 [Page 3] Internet-Draft react October 2020 it also allows MUAs that do support the mechanism to identify this redundant information and possibly remove it from display. 3. Usability Considerations This specification defines a mechanism for the structuring and carriage of information. It does not define any user-level details of use. However the design of the user-level mechanisms associated with this facility is paramount. This section discusses some issues to consider . Creation: Because an email environment is different from a typical social media platform, there are choices in the design of the user interface, to support indication of a reaction. Is the reaction to be sent only to the original author, or should it be sent to all recipients? Should the reaction always be sent in a discrete message containing only the reaction, or should the user also be able to include other message content? (Note that carriage of the reaction in a normal email message enables inclusion of this other content.) Display: Reaction indications might be more useful when displayed in close visual proximity to the original message, rather than merely as part of an email response thread. 4. Security Considerations This specification defines a distinct location for specialized message content. Processing that handles the content differently from content in the message body might introduce vulnerabilities. However the mere definition or use of this mechanism does not create new vulnerabilities. 5. IANA Considerations Add to "Permanent Message Header Field Registry": Header field name: In-Reply-React Applicable protocol: Mail (RFC 2822) Status: Experimental Author/Change controller: IETF Specification document(s): This specification. Crocker & Signes Expires April 19, 2021 [Page 4] Internet-Draft react October 2020 Related information: None 6. References 6.1. Normative References [ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 5234, January 2008. [Emoji-Seq] Davis, M., Ed. and P. Edberg., Ed., "Unicode(R) Technical Standard #51: Unicode Emoji", WEB http://www.unicode.org/reports/tr51/#def_emoji_sequence, September 2020. [Mail-Arch] Crocker, D., "Internet Mail Architecture", RFC 5598, July 2009. [Mail-Fmt] Resnick, P., Ed., "Internet Message Format", RFC 5322, October 2008. [MIME-Enc] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996. 6.2. Informative References [MIME] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. Appendix A. Acknowledgements This specification has been discussed in the ietf-822 mailing list. Active commentary and suggestions were offered by: Nathaniel Borenstein, Richard Clayton, Ned Freed, Bron Gondwana, Valdis Klētnieks, John Levine, Brandon Long, Keith Moore, Pete Resnick, Michael Richardson, Alessandro Vesely Authors' Addresses Dave Crocker Brandenburg InternetWorking Email: dcrocker@bbiw.net Crocker & Signes Expires April 19, 2021 [Page 5] Internet-Draft react October 2020 R. Signes Semiotic Systems Email: rjbs@semiotic.systems Crocker & Signes Expires April 19, 2021 [Page 6]