Editing Internationalized Resource Identifier (section)

== Compatibility ==
IRIs are mapped to URIs to retain backwards-compatibility with systems that do not support the new format.<ref name=rfc3987>{{cite journal|last1=Duerst|first1=M.|title=RFC 3987|journal=Network Working Group|date=2005|volume=Standards Track|url=http://tools.ietf.org/html/rfc3987|access-date=12 October 2014}}</ref>

For applications and protocols that do not allow direct consumption of IRIs, the IRI should first be converted to Unicode using [[Unicode equivalence|canonical composition normalization (NFC)]], if not already in Unicode format.

All non-ASCII code points in the IRI should next be encoded as [[UTF-8]], and the resulting bytes [[Percent-encoding|percent-encoded]], to produce a valid URI.

Example: The IRI https://en.wiktionary.org/wiki/Ῥόδος becomes the URI https://en.wiktionary.org/wiki/%E1%BF%AC%CF%8C%CE%B4%CE%BF%CF%82

ASCII code points that are invalid URI characters ''may'' be encoded the same way, depending on implementation.<ref name="rfc3987" />

This conversion is easily reversible; by definition, converting an IRI to an URI and back again will yield an IRI that is semantically equivalent to the original IRI, even though it may differ in exact representation.<ref>{{cite book|last1=Hendler|first1=Hrsg. Dieter Fensel; Hrsg. John Domingue; Hrsg. James A.|title=Handbook of Semantic Web Technologies|date=2010|publisher=Springer-Verlag GmbH|location=Berlin|isbn=978-3-540-92912-3|edition=1. Aufl.|url=https://books.google.com/books?id=sdEFvSb9WNsC|access-date=12 October 2014}}</ref>

Some protocols may impose further transformations; e.g. [[Punycode]] for [[Domain Name System|DNS]] labels.