Internationalized Resource Identifiers (IRIs)
RFC 3987
| Document | Type |
RFC - Proposed Standard
(January 2005; Errata)
Was draft-duerst-iri (individual in app area)
|
|
|---|---|---|---|
| Last updated | 2020-01-21 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 3987 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Ted Hardie | ||
| Send notices to | <mduerst@w3.org> | ||
Network Working Group M. Duerst
Request for Comments: 3987 W3C
Category: Standards Track M. Suignard
Microsoft Corporation
January 2005
Internationalized Resource Identifiers (IRIs)
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 (2005).
Abstract
This document defines a new protocol element, the Internationalized
Resource Identifier (IRI), as a complement to the Uniform Resource
Identifier (URI). An IRI is a sequence of characters from the
Universal Character Set (Unicode/ISO 10646). A mapping from IRIs to
URIs is defined, which means that IRIs can be used instead of URIs,
where appropriate, to identify resources.
The approach of defining a new protocol element was chosen instead of
extending or changing the definition of URIs. This was done in order
to allow a clear distinction and to avoid incompatibilities with
existing software. Guidelines are provided for the use and
deployment of IRIs in various protocols, formats, and software
components that currently deal with URIs.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview and Motivation . . . . . . . . . . . . . . . . 3
1.2. Applicability . . . . . . . . . . . . . . . . . . . . . 3
1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . 4
1.4. Notation . . . . . . . . . . . . . . . . . . . . . . . . 5
2. IRI Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1. Summary of IRI Syntax . . . . . . . . . . . . . . . . . 6
2.2. ABNF for IRI References and IRIs . . . . . . . . . . . . 7
Duerst & Suignard Standards Track [Page 1]
RFC 3987 Internationalized Resource Identifiers January 2005
3. Relationship between IRIs and URIs . . . . . . . . . . . . . . 10
3.1. Mapping of IRIs to URIs . . . . . . . . . . . . . . . . 10
3.2. Converting URIs to IRIs . . . . . . . . . . . . . . . . 14
3.2.1. Examples . . . . . . . . . . . . . . . . . . . . 15
4. Bidirectional IRIs for Right-to-Left Languages. . . . . . . . 16
4.1. Logical Storage and Visual Presentation . . . . . . . . 17
4.2. Bidi IRI Structure . . . . . . . . . . . . . . . . . . . 18
4.3. Input of Bidi IRIs . . . . . . . . . . . . . . . . . . . 19
4.4. Examples . . . . . . . . . . . . . . . . . . . . . . . . 19
5. Normalization and Comparison . . . . . . . . . . . . . . . . . 21
5.1. Equivalence . . . . . . . . . . . . . . . . . . . . . . 22
5.2. Preparation for Comparison . . . . . . . . . . . . . . . 22
5.3. Comparison Ladder . . . . . . . . . . . . . . . . . . . 23
5.3.1. Simple String Comparison . . . . . . . . . . . . 23
5.3.2. Syntax-Based Normalization . . . . . . . . . . . 24
5.3.3. Scheme-Based Normalization . . . . . . . . . . . 27
5.3.4. Protocol-Based Normalization . . . . . . . . . . 28
6. Use of IRIs . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1. Limitations on UCS Characters Allowed in IRIs . . . . . 29
6.2. Software Interfaces and Protocols . . . . . . . . . . . 29
6.3. Format of URIs and IRIs in Documents and Protocols . . . 30
6.4. Use of UTF-8 for Encoding Original Characters .. . . . . 30
6.5. Relative IRI References . . . . . . . . . . . . . . . . 32
7. URI/IRI Processing Guidelines (informative) . . . . . . . . . 32
7.1. URI/IRI Software Interfaces . . . . . . . . . . . . . . 32
7.2. URI/IRI Entry . . . . . . . . . . . . . . . . . . . . . 33
7.3. URI/IRI Transfer between Applications . . . . . . . . . 33
7.4. URI/IRI Generation . . . . . . . . . . . . . . . . . . . 34
7.5. URI/IRI Selection . . . . . . . . . . . . . . . . . . . 34
7.6. Display of URIs/IRIs . . . . . . . . . . . . . . . . . . 35
7.7. Interpretation of URIs and IRIs . . . . . . . . . . . . 36
7.8. Upgrading Strategy . . . . . . . . . . . . . . . . . . . 36
8. Security Considerations . . . . . . . . . . . . . . . . . . . 37
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 39
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10.1. Normative References . . . . . . . . . . . . . . . . . . 40
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