MailMaint D. Eggert, Ed. Internet-Draft Apple Inc Intended status: Informational 4 November 2024 Expires: 8 May 2025 IMAP "$MailFlagBit" Keywords draft-eggert-mailflagcolors-00 Abstract This document defines 3 new IMAP/JMAP keywords: $MailFlagBit0, $MailFlagBit1, and $MailFlagBit2 for specifying flag colors. It registers them with IANA to avoid name collisions. 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/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 8 May 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Eggert Expires 8 May 2025 [Page 1] Internet-Draft Abbreviated Title November 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 3. Definition of the MailFlagBit Message Keyword . . . . . . . . 3 4. Implementation Notes . . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. IMAP/JMAP Keyword Registrations . . . . . . . . . . . . . . . 4 6.1. $MailFlagBit0 keyword registration . . . . . . . . . . . 4 6.2. $MailFlagBit1 keyword registration . . . . . . . . . . . 4 6.3. $MailFlagBit2 keyword registration . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction The Internet Message Access Protocol (IMAP) specification [RFC9051] defines the use of message keywords, and an "IMAP Keywords" registry is created in [RFC5788]. [RFC9051] defines a \Flagged system flag to mark a message for urgent/special attention. The new keywords defined in this document allow such a flagged message to have that flag be of one of 7 colors. This document does the following: * defines 3 new message keywords, $MailFlagBit0, $MailFlagBit1, and $MailFlagBit2, to apply to any message that has the \Flagged keyword set; * registers these $MailFlagBit0, $MailFlagBit1, and $MailFlagBit2 keywords in the "IMAP Keywords" registry; * defines which combination of these flags correspond to which colors. 2. Requirements Language 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. Eggert Expires 8 May 2025 [Page 2] Internet-Draft Abbreviated Title November 2024 3. Definition of the MailFlagBit Message Keyword The 3 flag color keywords $MailFlagBit0, $MailFlagBit1, and $MailFlagBit2 make up a bit pattern that defined the color of the flag as such: +=======+=======+=======+========+ | Bit 0 | Bit 1 | Bit 2 | Color | +=======+=======+=======+========+ | 0 | 0 | 0 | red | +-------+-------+-------+--------+ | 1 | 0 | 0 | orange | +-------+-------+-------+--------+ | 0 | 1 | 0 | yellow | +-------+-------+-------+--------+ | 0 | 1 | 1 | green | +-------+-------+-------+--------+ | 0 | 0 | 1 | blue | +-------+-------+-------+--------+ | 1 | 0 | 1 | purple | +-------+-------+-------+--------+ | 0 | 1 | 1 | gray | +-------+-------+-------+--------+ Table 1 These flags SHOULD be ignored if the \Flagged system flag is not set. If the \Flagged system flag is set, the flagged status MAY be displayed to the user in the color corresponding to the combination of the 3 flag color keywords. 4. Implementation Notes A mail client that is aware of these flag color keywords SHOULD clear all 3 flag color keywords when the user unflags the message, i.e. when unsetting the \Flagged system flag, all 3 flag color keywords SHOULD also be unset. 5. IANA Considerations 3 IMAP/JMAP keywords are registered in the IMAP/JMAP keywords registry, as established in RFC5788. Eggert Expires 8 May 2025 [Page 3] Internet-Draft Abbreviated Title November 2024 6. IMAP/JMAP Keyword Registrations 6.1. $MailFlagBit0 keyword registration IMAP/JMAP keyword name: $MailFlagBit0 Purpose: 0 bit part of a 3-bit bitmask that defines the color of the flag when the has the system flag \Flagged set Private or Shared on a server: SHARED Is it an advisory keyword or may it cause an automatic action: No When/by whom the keyword is set/cleared: This keyword is set by an IMAP or JMAP client as the result of a user action to "flag" a message for urgent/special attention. Related keywords: $MailFlagBit1, $MailFlagBit2 Related IMAP capabilities: None Security considerations: None Published specification: This document Intended usage: COMMON Owner/Change controller: IESG 6.2. $MailFlagBit1 keyword registration IMAP/JMAP keyword name: $MailFlagBit1 Purpose: 0 bit part of a 3-bit bitmask that defines the color of the flag when the has the system flag \Flagged set Private or Shared on a server: SHARED Is it an advisory keyword or may it cause an automatic action: No When/by whom the keyword is set/cleared: This keyword is set by an IMAP or JMAP client as the result of a user action to "flag" a message for urgent/special attention. Related keywords: $MailFlagBit0, $MailFlagBit2 Related IMAP capabilities: None Eggert Expires 8 May 2025 [Page 4] Internet-Draft Abbreviated Title November 2024 Security considerations: None Published specification: This document Intended usage: COMMON Owner/Change controller: IESG 6.3. $MailFlagBit2 keyword registration IMAP/JMAP keyword name: $MailFlagBit2 Purpose: 0 bit part of a 3-bit bitmask that defines the color of the flag when the has the system flag \Flagged set Private or Shared on a server: SHARED Is it an advisory keyword or may it cause an automatic action: No When/by whom the keyword is set/cleared: This keyword is set by an IMAP or JMAP client as the result of a user action to "flag" a message for urgent/special attention. Related keywords: $MailFlagBit0, $MailFlagBit1 Related IMAP capabilities: None Security considerations: None Published specification: This document Intended usage: COMMON Owner/Change controller: IESG 7. Security Considerations This document should not affect the security of the Internet. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Eggert Expires 8 May 2025 [Page 5] Internet-Draft Abbreviated Title November 2024 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC9051] Melnikov, A., Ed. and B. Leiba, Ed., "Internet Message Access Protocol (IMAP) - Version 4rev2", RFC 9051, DOI 10.17487/RFC9051, August 2021, . [RFC5788] Melnikov, A. and D. Cridland, "IMAP4 Keyword Registry", RFC 5788, DOI 10.17487/RFC5788, March 2010, . Author's Address Daniel Eggert (editor) Apple Inc One Apple Park Way Cupertino, CA 95014 United States of America Email: deggert@apple.com URI: https://www.apple.com Eggert Expires 8 May 2025 [Page 6]