RFC 6648: Deprecating the "X-" Prefix and Similar Constructs in Application Protocols

Historically, designers and implementers of application protocols have often distinguished between standardized and unstandardized parameters by prefixing the…

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Outgoing relationships (30 related RFCs)

Informative reference — RFC 2119: Key words for use in RFCs to Indicate Requirement Levels
Informative reference — RFC 3986: Uniform Resource Identifier (URI): Generic Syntax
Informative reference — RFC 2045: Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
Informative reference — RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1
Informative reference — RFC 4566: SDP: Session Description Protocol
Informative reference — RFC 822: STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES
Informative reference — RFC 2046: Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types
Informative reference — RFC 1123: Requirements for Internet Hosts - Application and Support
Informative reference — RFC 2047: MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text
Informative reference — RFC 2822: Internet Message Format
Informative reference — RFC 5646: Tags for Identifying Languages
Informative reference — RFC 4288: Media Type Specifications and Registration Procedures
Informative reference — RFC 4122: A Universally Unique IDentifier (UUID) URN Namespace
Informative reference — RFC 3864: Registration Procedures for Message Header Fields
Informative reference — RFC 2068: Hypertext Transfer Protocol -- HTTP/1.1
Informative reference — RFC 4395: Guidelines and Registration Procedures for New URI Schemes
Informative reference — RFC 3406: Uniform Resource Names (URN) Namespace Definition Mechanisms
Informative reference — RFC 2426: vCard MIME Directory Profile
Informative reference — RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Informative reference — RFC 4512: Lightweight Directory Access Protocol (LDAP): Directory Information Models
Informative reference — RFC 5451: Message Header Field for Indicating Message Authentication Status
Informative reference — RFC 2939: Procedures and IANA Guidelines for Definition of New DHCP Options and Message Types
Informative reference — RFC 691: One more try on the FTP
Informative reference — RFC 5727: Change Process for the Session Initiation Protocol (SIP) and the Real-time Applications and Infrastructure Area
Informative reference — RFC 3427: Change Process for the Session Initiation Protocol (SIP)
Informative reference — RFC 775: Directory oriented FTP commands
Informative reference — RFC 1154: Encoding header field for internet messages
Informative reference — RFC 5064: The Archived-At Message Header Field
Informative reference — RFC 743: FTP extension: XRSQ/XRCP
Informative reference — RFC 737: FTP extension: XSEN

Incoming relationships (10 related RFCs)

Normatively referenced by — RFC 9205: Building Protocols with HTTP
Normatively referenced by — RFC 7960: Interoperability Issues between Domain-based Message Authentication, Reporting, and Conformance (DMARC) and Indirect Email Flows
Informatively referenced by — RFC 6838: Media Type Specifications and Registration Procedures
Informatively referenced by — RFC 6709: Design Considerations for Protocol Extensions
Informatively referenced by — RFC 7208: Sender Policy Framework (SPF) for Authorizing Use of Domains in Email, Version 1
Informatively referenced by — RFC 8141: Uniform Resource Names (URNs)
Informatively referenced by — RFC 7143: Internet Small Computer System Interface (iSCSI) Protocol (Consolidated)
Informatively referenced by — RFC 6963: A Uniform Resource Name (URN) Namespace for Examples
Informatively referenced by — RFC 7512: The PKCS #11 URI Scheme
Informatively referenced by — RFC 8098: Message Disposition Notification