Second-Level Reference Label Generation Rules
ICANN has developed second-level Internationalized Domain Name (IDN) tables in machine-readable format or Label Generation Rules (LGRs) that registry operators can reference while designing their IDN tables. These reference LGRs will be used by ICANN org when reviewing IDN tables submitted for use with the generic top-level domains (gTLDs).
The reference LGRs have been developed using guidelines, which have been reviewed by the community. These LGRs are provided below in the XML format along with a more readable HTML format.
If you have questions or feedback regarding these reference LGRs, please send an email to IDNprogram@icann.org.
Current Version (24 January 2024)
The current version of Second-Level Reference LGRs were developed in consultation with the respective script communities following detailed analysis of the Root Zone Label Generation Rules (RZ-LGR) and after a Public Comment proceeding.
This version includes:
- The script-based Reference LGRs including seven new scripts: Armenian, Cyrillic, Greek, Latin, Japanese, Korean, and Myanmar.
- In some cases, LGRs may be used in concert with other LGRs under a TLD. In such case, a set of "full-variant" LGR has been defined that collectively contain the suggested cross-script variants identified to mitigate whole-script homograph labels.
- A Common LGR has been created by merging the data from the script based LGRs. This file is intended for collision checking, particularly in the case where multiple LGRs are used in the same zone.
- Language LGRs which were derived a repertoire that is based on the Root Zone LGR but restricted to specific languages.
See the Overview and Summary document for further details about these LGRs. The package of all LGRs is available here [ZIP, 7.3MB]. The changes from previous are document in this change log document.
Script-based LGRs
| Name | Language Tag1 | LGR Document |
|---|---|---|
| Arabic | und-Arab | HTML, XML |
| Armenian | und-Armn | HTML, XML |
| Bangla (Bengali) | und-Beng | HTML, XML |
| Cyrillic | und-Cyrl | HTML, XML |
| Devanagari | und-Deva | HTML, XML |
| Ethiopic | und-Ethi | HTML, XML |
| Georgian | und-Geor | HTML, XML |
| Greek | und-Grek | HTML, XML |
| Gujarati | und-Gujr | HTML, XML |
| Gurmukhi | und-Guru | HTML, XML |
| Hebrew | und-Hebr | HTML, XML |
| Japanese | und-Jpan | HTML, XML |
| Kannada | und-Knda | HTML, XML |
| Khmer | und-Khmr | HTML, XML |
| Lao | und-Laoo | HTML, XML |
| Latin | und-Latn | HTML, XML |
| Malayalam | und-Mlym | HTML, XML |
| Myanmar | und-Mymr | HTML, XML |
| Oriya | und-Orya | HTML, XML |
| Sinhala | und-Sinh | HTML, XML |
| Tamil | und-Taml | HTML, XML |
| Telugu | und-Telu | HTML, XML |
| Thai | und-Thai | HTML, XML |
1: The prefix 'und' (Undetermined) identifies linguistic content whose language is not determined. Please see RFC5646 for details of the language tag syntax and IANA language sub tag registry for the available language tags.
Full Variant Set LGRs and Common LGR
| Name | Language Tag | Script Collection | LGR Document |
|---|---|---|---|
| Chinese (Full Variant Set) | und-Hani | Han used in Chinese, Korean, Japanese scripts | HTML, XML |
| Devanagari (Full Variant Set) | und-Deva | Devanagari, Bengali, and Gurmukhi | HTML, XML |
| Korean (Full Variant Set) | und-Kore | Hangul and Han used in Chinese and Korean script | HTML, XML |
| Latin (Full Variant Set) | und-Latn | Armenian, Cyrillic, Greek, Hebrew, and Latin | HTML, XML |
| Myanmar (Full Variant Set) | und-Mymr | Georgian, Latin, Malayalam, Myanmar, and Oriya | HTML, XML |
| Tamil (Full Variant Set) | und-Taml | Tamil and Malayalam | HTML, XML |
| Telugu (Full Variant Set) | und-Telu | Kannada and Telugu | HTML, XML |
| Common LGR | Multiple Tags | All scripts | HTML, XML |
Language-based LGRs
| Name | Language Tag2 | LGR Document |
|---|---|---|
| Arabic | ar | HTML, XML |
| Belarusian | be | HTML, XML |
| Bosnian (Cyrillic) | bs-Cyrl | HTML, XML |
| Bosnian (Latin) | bs | HTML, XML |
| Bulgarian | bg | HTML, XML |
| Chinese | zh | HTML, XML |
| Danish | da | HTML, XML |
| English | en | HTML, XML |
| Finnish | fi | HTML, XML |
| French | fr | HTML, XML |
| German | de | HTML, XML |
| Hebrew | he | HTML, XML |
| Hindi | hi | HTML, XML |
| Hungarian | hu | HTML, XML |
| Icelandic | is | HTML, XML |
| Italian | it | HTML, XML |
| Japanese (Standalone) | ja | HTML, XML |
| Korean (Hangul) | ko | HTML, XML |
| Latvian | lv | HTML, XML |
| Lithuanian | lt | HTML, XML |
| Macedonian | mk | HTML, XML |
| Montenegrin | cnr-Cyrl | HTML, XML |
| Norwegian | no | HTML, XML |
| Polish | pl | HTML, XML |
| Portuguese | pt | HTML, XML |
| Russian | ru | HTML, XML |
| Serbian | sr-Cyrl | HTML, XML |
| Spanish | es | HTML, XML |
| Swedish | sv | HTML, XML |
| Thai | th | HTML, XML |
| Ukrainian | uk | HTML, XML |
2: Where the default script is not identified, the script information is included to avoid ambiguity.
Archive
| Name | Language/ Script | Additional Information |
|---|---|---|
| Arabic | Language | Version 2,18 May 2021 (HTML, XML). Version 1, 13 January 2021 (HTML, XML) View public comment materials. |
| Arabic | Script | Version 2, 1 January 2022 (HTML, XML) Version 1, 22 April 2021 (HTML, XML) View public comment materials. |
| Bangla (Bengali) | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Belarusian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 19 December 2016 (HTML, XML) View public comment materials. |
| Bosnian (Cyrillic) | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Bosnian (Latin) | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Bulgarian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Chinese | Language | Version 2, 11 January 2022 (HTML, XML) Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Danish | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Devanagari | Script | Version 1: 15 December 2020 (HTML, XML) View public comment materials. |
| English | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Ethiopic | Script | Version1, 15 December 2020 (HTML, XML) View public comment materials. |
| Finnish | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| French | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Georgian | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| German | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Gujarati | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Gurmukhi | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Hebrew | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 22 April 2021 (HTML, XML) View public comment materials. |
| Hebrew | Script | Version 1, 22 April 2021 (HTML, XML) View public comment materials. |
| Hindi | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Hungarian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Icelandic | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Italian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Kannada | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Khmer | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Korean | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Lao | Script | Version 2, 22 April 2021 (HTML, XML) Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Latvian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Lithuanian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Macedonian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Malayalam | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Montenegrin | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Norwegian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Oriya | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Polish | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Portuguese | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Russian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Serbian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Sinhala | Script | Version 1, 22 April 2021 (HTML, XML) View public comment materials. |
| Spanish | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Swedish | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 10 October 2016 (HTML, XML) View public comment materials. |
| Tamil | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Telugu | Script | Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Thai | Language | Version 1, 18 May 2021 (HTML, XML) Version 1, 15 December 2020 (HTML, XML) View public comment materials. |
| Ukrainian | Language | Version 2, 18 May 2021 (HTML, XML) Version 1, 19 December 2016 (HTML, XML) View public comment materials. |