RFC 4289 · BEST CURRENT PRACTICE · 2005
MON · 27 JUL 2026
Multipurpose Internet Mail Extensions Part Four: Registration Procedures
Overview
RFC 4289, “Multipurpose Internet Mail Extensions Part Four: Registration Procedures”, is a Best Current Practice document published in December 2005 by N. Freed, J. Klensin. It obsoletes RFC 2048. The canonical text is published by the RFC Editor.
Abstract
This document specifies IANA registration procedures for MIME external body access types and content-transfer-encodings. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.
What “Best Current Practice” means
Documents the IETF community's recommended operational or procedural practice rather than a protocol specification.
Read this RFC
The canonical text of RFC 4289 is hosted at rfc-editor.org. Available in TXT,HTML.
Relationships to other RFCs
Other RFCs from 2005
- RFC 4288 Media Type Specifications and Registration Procedures
- RFC 4290 Suggested Practices for Registration of Internationalized Domain Names
- RFC 4287 The Atom Syndication Format
- RFC 4286 Multicast Router Discovery
- RFC 4283 Mobile Node Identifier Option for Mobile IPv6
- RFC 4282 The Network Access Identifier
- RFC 4296 The Architecture of Direct Data Placement and Remote Direct Memory Access on Internet Protocols
- RFC 4281 The Codecs Parameter for "Bucket" Media Types