Comparison, Equivalence and Canonicalization of Internationalized Resource Identifiers

Document Type Expired Internet-Draft (individual)
Last updated 2015-10-14 (latest revision 2012-10-22)
Replaces draft-masinter-iri-comparison
Stream IETF
Intended RFC status Proposed Standard
Expired & archived
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Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired (IESG: Dead)
Telechat date
Responsible AD Pete Resnick
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


Internationalized Resource Identifiers (IRIs) are Unicode strings used to identify resources on the Internet. Applications that use IRIs often define a means of comparing IRIs to determine when two IRIs are equivalent for the purpose of that application. Some applications also define a method for canonicalizing an IRI -- translating one IRI into another which is equivalent under the comparison method used. This document gives guidelines and best practices for defining and using IRI comparison and canonicalization methods. Comparison methods are used to determine equivalence. As URIs are a subset of IRIs, the guidelines apply to URI comparison as well.


Larry Masinter (
Martin Dürst (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)