This file lists RFC's that are relevant for email, along with implementation
status. "make" fetches the RFC's and adds references back to the source code
where they are referenced. The protocol support page on the website is
generated from this information as well.

Each tab-separated row has:
- RFC number
- Support/implementation status
- RFC status (e.g. Obs for obsolete)
- RFC title

If the support status column value starts with a minus, it isn't included on
the protocol page on the website. Valid words for implementation status:
- Yes, support is deemed complete
- Partial, support is partial, more work can be done
- Roadmap, no support, but it is planned
- No, not supported and no plans
- ?, implementation status unknown

Also see IANA assignments, https://www.iana.org/protocols


# Internet Message Format
822	Yes	Obs	Standard for ARPA Internet Text Messages
1847	No	-	Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted
2045	Yes	-	Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
2046	Yes	-	Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types
2047	Yes	-	MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text
2049	-	-	Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples
2076	-	-	Common Internet Message Headers
2183	Yes	-	Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field
2231	Yes	-	MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations
3629	-	-	UTF-8, a transformation format of ISO 10646
3676	No	- 	The Text/Plain Format and DelSp Parameters
3834	Roadmap	-	Recommendations for Automatic Responses to Electronic Mail
5234	-	-	Augmented BNF for Syntax Specifications: ABNF
5322	Yes	-	Internet Message Format
5598	-	-	Internet Mail Architecture
6854	-	-	Update to Internet Message Format to Allow Group Syntax in the "From:" and "Sender:" Header Fields
7405	-	-	Case-Sensitive String Support in ABNF
9078	-	-	Reaction: Indicating Summary Reaction to a Message
9228	Yes	-	Delivered-To Email Header Field

https://www.iana.org/assignments/message-headers/message-headers.xhtml

# SMTP
821	Yes	Obs	(RFC 2821) SIMPLE MAIL TRANSFER PROTOCOL
2821	Yes	Obs	(RFC 5321) Simple Mail Transfer Protocol
5321	Yes	-	Simple Mail Transfer Protocol

1870	Yes	-	SMTP Service Extension for Message Size Declaration
1985	No	-	SMTP Service Extension for Remote Message Queue Starting
2034	Yes	-	SMTP Service Extension for Returning Enhanced Error Codes
2852	No	-	Deliver By SMTP Service Extension
2920	Yes	-	SMTP Service Extension for Command Pipelining
2505	-	-	Anti-Spam Recommendations for SMTP MTAs
3207	Yes	-	SMTP Service Extension for Secure SMTP over Transport Layer Security (STARTTLS)
3030	Roadmap	-	SMTP Service Extensions for Transmission of Large and Binary MIME Messages
3461	Roadmap	-	Simple Mail Transfer Protocol (SMTP) Service Extension for Delivery Status Notifications (DSNs)
3462	-	Obs	(RFC 6522) The Multipart/Report Content Type for the Reporting of Mail System Administrative Messages
3463	Yes	-	Enhanced Mail System Status Codes
3464	Yes	-	An Extensible Message Format for Delivery Status Notifications
3798	?	Obs	(RFC 8098) Message Disposition Notification
3848	-	-	ESMTP and LMTP Transmission Types Registration
3865	No	-	A No Soliciting Simple Mail Transfer Protocol (SMTP) Service Extension
3885	No	-	SMTP Service Extension for Message Tracking
3974	-	-	SMTP Operational Experience in Mixed IPv4/v6 Environments
4409	-	Obs	(RFC 6409) Message Submission for Mail
4468	Roadmap	-	Message Submission BURL Extension
4865	Yes	-	SMTP Submission Service Extension for Future Message Release
4865-eid2040	-Yes	-	errata: Internet-style-date-time-UTC -> date-time from rfc 3339
4954	Yes	-	SMTP Service Extension for Authentication
5068	-	-	Email Submission Operations: Access and Accountability Requirements
5248	-	-	A Registry for SMTP Enhanced Mail System Status Codes
5335	-	Obs	(RFC 6532) Internationalized Email Headers
5336	-	Obs	(RFC 6531) SMTP Extension for Internationalized Email Addresses
5337	-	Obs	(RFC 6533) Internationalized Delivery Status and Disposition Notifications
5782	Yes	-	DNS Blacklists and Whitelists
6008	Yes	-	Authentication-Results Registration for Differentiating among Cryptographic Results
6152	Yes	-	SMTP Service Extension for 8-bit MIME Transport
6409	Yes	-	Message Submission for Mail
6522	Yes	-	The Multipart/Report Media Type for the Reporting of Mail System Administrative Messages
6530	Yes	-	Overview and Framework for Internationalized Email
6531	Yes	-	SMTP Extension for Internationalized Email
6532	Yes	-	Internationalized Email Headers
6533	Yes	-	Internationalized Delivery Status and Disposition Notifications
6647	Partial	-	Email Greylisting: An Applicability Statement for SMTP
6710	No	-	Simple Mail Transfer Protocol Extension for Message Transfer Priorities
6729	No	-	Indicating Email Handling States in Trace Fields
6857	No	-	Post-Delivery Message Downgrading for Internationalized Email Messages
7293	No	-	The Require-Recipient-Valid-Since Header Field and SMTP Service Extension
7372	Yes	-	Email Authentication Status Codes
7435	Yes	-	Opportunistic Security: Some Protection Most of the Time
7504	Yes	-	SMTP 521 and 556 Reply Codes
7505	Yes	-	A "Null MX" No Service Resource Record for Domains That Accept No Mail
8098	?	-	Message Disposition Notification
8601	Yes	-	Message Header Field for Indicating Message Authentication Status
8689	Yes	-	SMTP Require TLS Option
8904	No	-	DNS Whitelist (DNSWL) Email Authentication Method Extension
9422	Yes	-	The LIMITS SMTP Service Extension

# SPF
4408	Yes	Obs	(by RFC 7208) Sender Policy Framework (SPF) for Authorizing Use of Domains in E-Mail, Version 1
6652	?	-	Sender Policy Framework (SPF) Authentication Failure Reporting Using the Abuse Reporting Format
7208	Yes	-	Sender Policy Framework (SPF) for Authorizing Use of Domains in Email, Version 1
7208-eid5436	-	-	errata: header-field FWS
7208-eid6721	-	-	errata: corrected smtp example response
7208-eid4751	-	-	errata (not verified): ptr mechanism
7208-eid5227	-	-	errata (not verified): ptr lookup order
7208-eid6595	-	-	errata (not verified): 2 void lookups vs exists
7208-eid6216	-	-	errata (not verified): ptr in multiple requirements example from appendix A.4

# DKIM
6376	Yes	-	DomainKeys Identified Mail (DKIM) Signatures
6376-eid4810	-	-	errata: q= qp-hdr-value
6376-eid5070	-	-	errata: tag-spec

4686	-	-	Analysis of Threats Motivating DomainKeys Identified Mail (DKIM)
4871	Yes	Obs	(RFC 6376) DomainKeys Identified Mail (DKIM) Signatures
5016	-Yes	-	Requirements for a DomainKeys Identified Mail (DKIM) Signing Practices Protocol
5585	-Yes	-	DomainKeys Identified Mail (DKIM) Service Overview
5672	-Yes	Obs	(by RFC 6376) DomainKeys Identified Mail (DKIM) Signatures -- Update
5863	-Yes	-	DomainKeys Identified Mail (DKIM) Development, Deployment, and Operations
6377	?	-	DomainKeys Identified Mail (DKIM) and Mailing Lists
8032	-	-	Edwards-Curve Digital Signature Algorithm (EdDSA)
8301	Yes	-	Cryptographic Algorithm and Key Usage Update to DomainKeys Identified Mail (DKIM)
8463	Yes	-	A New Cryptographic Signature Method for DomainKeys Identified Mail (DKIM)

# DMARC
7489	Yes	-	Domain-based Message Authentication, Reporting, and Conformance (DMARC)
7489-eid5440	-	-	errata: valid dmarc records with(out) semicolon
7489-eid6729	-	-	errata (not verified): publicsuffix list only for ICANN DOMAINS
7960	Yes	-	Interoperability Issues between Domain-based Message Authentication, Reporting, and Conformance (DMARC) and Indirect Email Flows
9091	Roadmap	-	Experimental Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Extension for Public Suffix Domains

# ARC
8617	Roadmap	-	The Authenticated Received Chain (ARC) Protocol

# DANE
6394	-Yes	-	Use Cases and Requirements for DNS-Based Authentication of Named Entities (DANE)
6698	Yes	-	The DNS-Based Authentication of Named Entities (DANE) Transport Layer Security (TLS) Protocol: TLSA
7218	-Yes	-	Adding Acronyms to Simplify Conversations about DNS-Based Authentication of Named Entities (DANE)
7671	-Yes	-	The DNS-Based Authentication of Named Entities (DANE) Protocol: Updates and Operational Guidance
7672	Yes	-	SMTP Security via Opportunistic DNS-Based Authentication of Named Entities (DANE) Transport Layer Security (TLS)
7673	Roadmap	-	Using DNS-Based Authentication of Named Entities (DANE) TLSA Records with SRV Records
7929	No	-	DNS-Based Authentication of Named Entities (DANE) Bindings for OpenPGP
8162	No	-	Using Secure DNS to Associate Certificates with Domain Names for S/MIME

# MTA-STS
8461	Yes	-	SMTP MTA Strict Transport Security (MTA-STS)

# TLS Reporting
8460	Yes	-	SMTP TLS Reporting
8460-eid6241	-	-	Wrong example for JSON field "mx-host".

# ARF
5965	Roadmap	-	An Extensible Format for Email Feedback Reports
6650	Roadmap	-	Creation and Use of Email Feedback Reports: An Applicability Statement for the Abuse Reporting Format (ARF)
6591	?	-	Authentication Failure Reporting Using the Abuse Reporting Format
6692	Roadmap	-	Source Ports in Abuse Reporting Format (ARF) Reports
9477	Roadmap	-	Complaint Feedback Loop Address Header

# IMAP
1730	Yes	Obs	(RFC 2060) INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4
2060	Yes	Obs	(RFC 3501) INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1
3501	Yes	Obs	(RFC 9051) INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1
9051	Yes	-	Internet Message Access Protocol (IMAP) - Version 4rev2

1733	-Yes	-	DISTRIBUTED ELECTRONIC MAIL MODELS IN IMAP4
2087	Roadmap	-	IMAP4 QUOTA extension
2088	-	Obs	(RFC 7888) IMAP4 non-synchronizing literals
2152	Yes	-	UTF-7 A Mail-Safe Transformation Format of Unicode
2177	Yes	-	IMAP4 IDLE command
2180	Yes	-	IMAP4 Multi-Accessed Mailbox Practice
2193	No	-	IMAP4 Mailbox Referrals
2342	Yes	-	IMAP4 Namespace
2683	Yes	-	IMAP4 Implementation Recommendations
2971	Yes	-	IMAP4 ID extension
3348	Yes	Obs	(RFC 5258) The Internet Message Action Protocol (IMAP4) Child Mailbox Extension
3502	Roadmap	-	Internet Message Access Protocol (IMAP) - MULTIAPPEND Extension
3503	?	-	Message Disposition Notification (MDN) profile for Internet Message Access Protocol (IMAP)
3516	Yes	-	IMAP4 Binary Content Extension
3691	Yes	-	Internet Message Access Protocol (IMAP) UNSELECT command
4314	Roadmap	-	IMAP4 Access Control List (ACL) Extension
4315	Yes	-	Internet Message Access Protocol (IMAP) - UIDPLUS extension
4466	-Yes	-	Collected Extensions to IMAP4 ABNF
4467	Roadmap	-	Internet Message Access Protocol (IMAP) - URLAUTH Extension
4469	Roadmap	-	Internet Message Access Protocol (IMAP) CATENATE Extension
4549	-Yes	-	Synchronization Operations for Disconnected IMAP4 Clients
4551	Yes	Obs	(RFC 7162) IMAP Extension for Conditional STORE Operation or Quick Flag Changes Resynchronization
4731	Yes	-	IMAP4 Extension to SEARCH Command for Controlling What Kind of Information Is Returned
4959	Yes	-	IMAP Extension for Simple Authentication and Security Layer (SASL) Initial Client Response
4978	Roadmap	-	The IMAP COMPRESS Extension
5032	Roadmap	-	WITHIN Search Extension to the IMAP Protocol
5092	Roadmap	-	IMAP URL Scheme
5161	Yes	-	The IMAP ENABLE Extension
5162	Yes	Obs	(RFC 7162) IMAP4 Extensions for Quick Mailbox Resynchronization
5182	Yes	-	IMAP Extension for Referencing the Last SEARCH Result
5255	No	-	Internet Message Access Protocol Internationalization
5256	Roadmap	-	Internet Message Access Protocol - SORT and THREAD Extensions
5257	No	-	Internet Message Access Protocol - ANNOTATE Extension
5258	Yes	-	Internet Message Access Protocol version 4 - LIST Command Extensions
5259	No	-	Internet Message Access Protocol - CONVERT Extension
5267	Roadmap	-	Contexts for IMAP4
5464	Roadmap	-	The IMAP METADATA Extension
5465	Roadmap	-	The IMAP NOTIFY Extension
5466	Roadmap	-	IMAP4 Extension for Named Searches (Filters)
5524	No	-	Extended URLFETCH for Binary and Converted Parts
5530	Yes	-	IMAP Response Codes
5738	Partial	Obs	(RFC 6855) IMAP Support for UTF-8
5788	-Yes	-	IMAP4 Keyword Registry
5819	Yes	-	IMAP4 Extension for Returning STATUS Information in Extended LIST
5957	Roadmap	-	Display-Based Address Sorting for the IMAP4 SORT Extension
6154	Yes	-	IMAP LIST Extension for Special-Use Mailboxes
6203	No	-	IMAP4 Extension for Fuzzy Search
6237	Roadmap	Obs	(RFC 7377) IMAP4 Multimailbox SEARCH Extension
6851	Yes	-	Internet Message Access Protocol (IMAP) - MOVE Extension
6855	Yes	-	IMAP Support for UTF-8
6858	No	-	Simplified POP and IMAP Downgrading for Internationalized Email
7162	Yes	-	IMAP Extensions: Quick Flag Changes Resynchronization (CONDSTORE) and Quick Mailbox Resynchronization (QRESYNC)
7162-eid5055	-	-	errata: space after untagged OK
7377	Roadmap	-	IMAP4 Multimailbox SEARCH Extension
7888	Yes	-	IMAP4 Non-synchronizing Literals
7889	Yes	-	The IMAP APPENDLIMIT Extension
8437	Roadmap	-	IMAP UNAUTHENTICATE Extension for Connection Reuse
8438	Yes	-	IMAP Extension for STATUS=SIZE
8440	?	-	IMAP4 Extension for Returning MYRIGHTS Information in Extended LIST
8457	Roadmap	-	IMAP "$Important" Keyword and "\Important" Special-Use Attribute
8474	Roadmap	-	IMAP Extension for Object Identifiers
8508	Roadmap	-	IMAP REPLACE Extension
8514	Roadmap	-	Internet Message Access Protocol (IMAP) - SAVEDATE Extension
8970	Roadmap	-	IMAP4 Extension: Message Preview Generation
9208	Roadmap	-	IMAP QUOTA Extension
9394	Roadmap	-	IMAP PARTIAL Extension for Paged SEARCH and FETCH

5198	-?	-	Unicode Format for Network Interchange

# Lemonade profile
4550	-?	Obs	(RFC 5550) Internet Email to Support Diverse Service Environments (Lemonade) Profile
5383	-?	-	Deployment Considerations for Lemonade-Compliant Mobile Email
5423	-?	-	Internet Message Store Events
5442	-?	-	LEMONADE Architecture - Supporting Open Mobile Alliance (OMA) Mobile Email (MEM) Using Internet Mail
5550	-?	-	The Internet Email to Support Diverse Service Environments (Lemonade) Profile
5551	-?	-	Lemonade Notifications Architecture

# Mailing list and automated responses
2369	?	-	The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields
2919	?	-	List-Id: A Structured Field and Namespace for the Identification of Mailing Lists
3834 	?	-	Recommendations for Automatic Responses to Electronic Mail
8058	?	-	Signaling One-Click Functionality for List Email Headers

# Sieve
3028	Roadmap	Obs	(RFC 5228) Sieve: A Mail Filtering Language
5228	Roadmap	-	Sieve: An Email Filtering Language
5804	Roadmap	-	A Protocol for Remotely Managing Sieve Scripts

3894	No	-	Sieve Extension: Copying Without Side Effects
5173	No	-	Sieve Email Filtering: Body Extension
5183	Roadmap	-	Sieve Email Filtering: Environment Extension
5229	Roadmap	-	Sieve Email Filtering: Variables Extension
5230	Roadmap	-	Sieve Email Filtering: Vacation Extension
5231	Roadmap	-	Sieve Email Filtering: Relational Extension
5232	Roadmap	-	Sieve Email Filtering: Imap4flags Extension
5233	Roadmap	-	Sieve Email Filtering: Subaddress Extension
5235	No	-	Sieve Email Filtering: Spamtest and Virustest Extensions
5260	No	-	Sieve Email Filtering: Date and Index Extensions
5293	No	-	Sieve Email Filtering: Editheader Extension
5429	Roadmap	-	Sieve Email Filtering: Reject and Extended Reject Extensions
5435	No	-	Sieve Email Filtering: Extension for Notifications
5437	No	-	Sieve Notification Mechanism: Extensible Messaging and Presence Protocol (XMPP)
5463	Roadmap	-	Sieve Email Filtering:  Ihave Extension
5490	No	-	The Sieve Mail-Filtering Language -- Extensions for Checking Mailbox Status and Accessing Mailbox Metadata
5703	No	-	Sieve Email Filtering: MIME Part Tests, Iteration, Extraction, Replacement, and Enclosure
5784	No	-	Sieve Email Filtering:  Sieves and Display Directives in XML
6131	?	-	Sieve Vacation Extension: "Seconds" Parameter
6558	No	-	Sieve Extension for Converting Messages before Delivery
6609	No	-	Sieve Email Filtering: Include Extension
6785	Roadmap	-	Support for Internet Message Access Protocol (IMAP) Events in Sieve
8579	Roadmap	-	Sieve Email Filtering: Delivering to Special-Use Mailboxes
8580	No	-	Sieve Extension: File Carbon Copy (FCC)
9042	No	-	Sieve Email Filtering: Delivery by MAILBOXID

3431	Roadmap	Obs	(RFC 5231) Relational Extension
3598	Roadmap	Obs	(RFC 5233) Subaddress Extension
3685	No	Obs	(RFC 5235) Spamtest and VirusTest Extensions

Also see http://sieve.info/documents

# JMAP
8620	Roadmap	-	The JSON Meta Application Protocol (JMAP)
8621	Roadmap	-	The JSON Meta Application Protocol (JMAP) for Mail
8887	Roadmap	-	A JSON Meta Application Protocol (JMAP) Subprotocol for WebSocket
9007	?	-	Handling Message Disposition Notification with the JSON Meta Application Protocol (JMAP)
9219	No	-	S/MIME Signature Verification Extension to the JSON Meta Application Protocol (JMAP)
9425	No	-	JSON Meta Application Protocol (JMAP) for Quotas

See implementation guide, https://jmap.io/server.html

# CalDAV/iCal
4791	Roadmap	-	Calendaring Extensions to WebDAV (CalDAV)
5689	Roadmap	-	Extended MKCOL for Web Distributed Authoring and Versioning (WebDAV)
6638	Roadmap	-	Scheduling Extensions to CalDAV
6764	Roadmap	-	Locating Services for Calendaring Extensions to WebDAV (CalDAV) and vCard Extensions to WebDAV (CardDAV)
7809	Roadmap	-	Calendaring Extensions to WebDAV (CalDAV): Time Zones by Reference
7953	Roadmap	-	Calendar Availability

5545	Roadmap	-	Internet Calendaring and Scheduling Core Object Specification (iCalendar)
5546	Roadmap	-	iCalendar Transport-Independent Interoperability Protocol (iTIP)
6047	Roadmap	-	iCalendar Message-Based Interoperability Protocol (iMIP)
6868	Roadmap	-	Parameter Value Encoding in iCalendar and vCard
7529	?	-	Non-Gregorian Recurrence Rules in the Internet Calendaring and Scheduling Core Object Specification (iCalendar)
7986	?	-	New Properties for iCalendar
9073	?	-	Event Publishing Extensions to iCalendar
9074	?	-	"VALARM" Extensions for iCalendar
9253	?	-	Support for iCalendar Relationships
6321	?	-	xCal: The XML Format for iCalendar
7265	?	-	jCal: The JSON Format for iCalendar

# CardDAV/vCard
6352	Roadmap	-	CardDAV: vCard Extensions to Web Distributed Authoring and Versioning (WebDAV)

2425	Roadmap	-	A MIME Content-Type for Directory Information
2426	?	-	vCard MIME Directory Profile
6350	Roadmap	-	vCard Format Specification
6351	?	-	xCard: vCard XML Representation
6473	?	-	vCard KIND:application
6474	?	-	vCard Format Extensions: Place of Birth, Place and Date of Death
6715	?	-	vCard Format Extensions: Representing vCard Extensions Defined by the Open Mobile Alliance (OMA) Converged Address Book (CAB) Group
6869	?	-	vCard KIND:device
7095	?	-	jCard: The JSON Format for vCard

# WebDAV
4918	Roadmap	-	HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)
3253	?	-	Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)
3648	?	-	Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol
3744	?	-	Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol
4437	?	-	Web Distributed Authoring and Versioning (WebDAV) Redirect Reference Resources
5323	?	-	Web Distributed Authoring and Versioning (WebDAV) SEARCH
6578	?	-	Collection Synchronization for Web Distributed Authoring and Versioning (WebDAV)

# SASL
2104	-	-	HMAC: Keyed-Hashing for Message Authentication
2195	Yes	-	IMAP/POP AUTHorize Extension for Simple Challenge/Response
4013	Yes	Obs	(RFC 7613) SASLprep: Stringprep Profile for User Names and Passwords
4422	Yes	-	Simple Authentication and Security Layer (SASL)
4505	No	-	Anonymous Simple Authentication and Security Layer (SASL) Mechanism
4616	Yes	-	The PLAIN Simple Authentication and Security Layer (SASL) Mechanism
5802	Yes	-	Salted Challenge Response Authentication Mechanism (SCRAM) SASL and GSS-API Mechanisms
6331	-No	-	Moving DIGEST-MD5 to Historic
7613	Yes	Obs	(RFC 8265) Preparation, Enforcement, and Comparison of Internationalized Strings Representing Usernames and Passwords
7677	Yes	-	SCRAM-SHA-256 and SCRAM-SHA-256-PLUS Simple Authentication and Security Layer (SASL) Mechanisms
8265	Yes	-	Preparation, Enforcement, and Comparison of Internationalized Strings Representing Usernames and Passwords

# Internationalization
3492	Yes	-	Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)
5890	Yes	-	Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework
5891	Yes	-	Internationalized Domain Names in Applications (IDNA): Protocol
5892	?	-	The Unicode Code Points and Internationalized Domain Names for Applications (IDNA)
5893	?	-	Right-to-Left Scripts for Internationalized Domain Names for Applications (IDNA)
5894	?	-	Internationalized Domain Names for Applications (IDNA): Background, Explanation, and Rationale
8616	Yes	-	Email Authentication for Internationalized Mail

# TLS
5056	Yes	-	On the Use of Channel Bindings to Secure Channels
5705	Yes	-	Keying Material Exporters for Transport Layer Security (TLS)
5929	Yes	-	Channel Bindings for TLS
6125	-?	-	Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)
7250	-No	-	Using Raw Public Keys in Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)
7525	-?	-	Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)
7627	-?	-	Transport Layer Security (TLS) Session Hash and Extended Master Secret Extension
8314	Yes	-	Cleartext Considered Obsolete: Use of Transport Layer Security (TLS) for Email Submission and Access
8446	Yes	-	The Transport Layer Security (TLS) Protocol Version 1.3
8996	Yes	-	Deprecating TLS 1.0 and TLS 1.1
8997	Yes	-	Deprecation of TLS 1.1 for Email Submission and Access
9266	Yes	-	Channel Bindings for TLS 1.3

# ACME
8555	Yes	-	Automatic Certificate Management Environment (ACME)
8737	Yes	-	Automated Certificate Management Environment (ACME) TLS Application-Layer Protocol Negotiation (ALPN) Challenge Extension

# CAA
8659	Yes	-	DNS Certification Authority Authorization (CAA) Resource Record
8657	Yes	-	Certification Authority Authorization (CAA) Record Extensions for Account URI and Automatic Certificate Management Environment (ACME) Method Binding

# Vouch by reference
5518	-?	-	Vouch By Reference

# HTTP
2616	Yes	Obs	(RFC 7230) Hypertext Transfer Protocol -- HTTP/1.1
6455	Yes	-	The WebSocket Protocol
7230	Yes	Obs	(RFC 9110) Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
9110	Yes	-	HTTP Semantics


# More
3339	-?	-	Date and Time on the Internet: Timestamps
3986	-?	-	Uniform Resource Identifier (URI): Generic Syntax
5617	-?	-	(Historic) DomainKeys Identified Mail (DKIM) Author Domain Signing Practices (ADSP)
6068	-Yes	-	The 'mailto' URI Scheme
6186	-?	-	(not used in practice) Use of SRV Records for Locating Email Submission/Access Services
7817	-?	-	Updated Transport Layer Security (TLS) Server Identity Check Procedure for Email-Related Protocols

# DNS
1034	-?	-	DOMAIN NAMES - CONCEPTS AND FACILITIES
1035	-?	-	DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
1101	-?	-	DNS Encoding of Network Names and Other Types
1536	-?	-	Common DNS Implementation Errors and Suggested Fixes
2181	-?	-	Clarifications to the DNS Specification
2308	-?	-	Negative Caching of DNS Queries (DNS NCACHE)
2672	-?	-	(obsoleted by RFC 6672) Non-Terminal DNS Name Redirection
3226	-?	-	DNSSEC and IPv6 A6 aware server/resolver message size requirements
3363	-?	-	Representing Internet Protocol version 6 (IPv6) Addresses in the Domain Name System (DNS)
3596	-?	-	DNS Extensions to Support IP Version 6
3597	-?	-	Handling of Unknown DNS Resource Record (RR) Types
3833	-?	-	Threat Analysis of the Domain Name System (DNS)
4343	-?	-	Domain Name System (DNS) Case Insensitivity Clarification
4592	-?	-	The Role of Wildcards in the Domain Name System
5001	-?	-	DNS Name Server Identifier (NSID) Option
5452	-?	-	Measures for Making DNS More Resilient against Forged Answers
6604	-?	-	xNAME RCODE and Status Bits Clarification
6672	-?	-	DNAME Redirection in the DNS
6891	-?	-	Extension Mechanisms for DNS (EDNS(0))
6895	-?	-	Domain Name System (DNS) IANA Considerations
7686	-?	-	The ".onion" Special-Use Domain Name
7766	-?	-	DNS Transport over TCP - Implementation Requirements
7828	-?	-	The edns-tcp-keepalive EDNS0 Option
7873	-?	-	Domain Name System (DNS) Cookies
8020	-?	-	NXDOMAIN: There Really Is Nothing Underneath
8482	-?	-	Providing Minimal-Sized Responses to DNS Queries That Have QTYPE=ANY
8490	-?	-	DNS Stateful Operations
8499	-?	-	DNS Terminology
8767	-?	-	Serving Stale Data to Improve DNS Resiliency
8914	-?	-	Extended DNS Errors
9018	-?	-	Interoperable Domain Name System (DNS) Server Cookies
9210	-?	-	DNS Transport over TCP - Operational Requirements

# DNSSEC
3225	-?	-	Indicating Resolver Support of DNSSEC
3658	-?	-	Delegation Signer (DS) Resource Record (RR)
4033	-?	-	DNS Security Introduction and Requirements
4034	-?	-	Resource Records for the DNS Security Extensions
4035	-?	-	Protocol Modifications for the DNS Security Extensions
4470	-?	-	Minimally Covering NSEC Records and DNSSEC On-line Signing
4956	-?	-	DNS Security (DNSSEC) Opt-In
5155	-?	-	DNS Security (DNSSEC) Hashed Authenticated Denial of Existence
5702	-?	-	Use of SHA-2 Algorithms with RSA in DNSKEY and RRSIG Resource Records for DNSSEC
5933	-?	-	Use of GOST Signature Algorithms in DNSKEY and RRSIG Resource Records for DNSSEC
6014	-?	-	Cryptographic Algorithm Identifier Allocation for DNSSEC
6781	-?	-	DNSSEC Operational Practices, Version 2
6840	-?	-	Clarifications and Implementation Notes for DNS Security (DNSSEC)
7901	-?	-	CHAIN Query Requests in DNS
8198	-?	-	Aggressive Use of DNSSEC-Validated Cache
8624	-?	-	Algorithm Implementation Requirements and Usage Guidance for DNSSEC
8749	-?	-	Moving DNSSEC Lookaside Validation (DLV) to Historic Status
9077	-?	-	NSEC and NSEC3: TTLs and Aggressive Use
9157	-?	-	Revised IANA Considerations for DNSSEC
9276	-?	-	Guidance for NSEC3 Parameter Settings
