RFC 3490 (rfc3490) - Page 1 of 22
Internationalizing Domain Names in Applications (IDNA)
Alternative Format: Original Text Document
Network Working Group P. Faltstrom
Request for Comments: 3490 Cisco
Category: Standards Track P. Hoffman
IMC & VPNC
A. Costello
UC Berkeley
March 2003
Internationalizing Domain Names in Applications (IDNA)
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
Until now, there has been no standard method for domain names to use
characters outside the ASCII repertoire. This document defines
internationalized domain names (IDNs) and a mechanism called
Internationalizing Domain Names in Applications (IDNA) for handling
them in a standard fashion. IDNs use characters drawn from a large
repertoire (Unicode), but IDNA allows the non-ASCII characters to be
represented using only the ASCII characters already allowed in so-
called host names today. This backward-compatible representation is
required in existing protocols like DNS, so that IDNs can be
introduced with no changes to the existing infrastructure. IDNA is
only meant for processing domain names, not free text.
Table of Contents
1. Introduction.................................................. 2
1.1 Problem Statement......................................... 3
1.2 Limitations of IDNA....................................... 3
1.3 Brief overview for application developers................. 4
2. Terminology................................................... 5
3. Requirements and applicability................................ 7
3.1 Requirements.............................................. 7
3.2 Applicability............................................. 8
3.2.1. DNS resource records................................ 8
Faltstrom, et al. Standards Track