ICANN opens consultation on updated unicode reference for internet domain names
ICANN is inviting feedback on the sixth version of the Maximal Starting Repertoire (MSR-6), which determines which Unicode characters can be safely used in internationalized domain names. The update aims to expand linguistic diversity online while maintaining security and stability.
The Internet Corporation for Assigned Names and Numbers (ICANN) is seeking public input on the sixth version of the Maximal Starting Repertoire (MSR-6), a technical reference that helps determine which characters from the Unicode standard can be used in internet domain names.
What is the maximal starting repertoire?
The Maximal Starting Repertoire (MSR) is a filtered list of Unicode characters that can potentially be used to create Internationalised Domain Names (IDNs)—domain names that include scripts and languages beyond the basic Latin alphabet, such as Arabic, Chinese, or Cyrillic.
Unicode is the global coding system that assigns every character in every language a unique number. However, not all characters are suitable for use in the Internet’s root zone (the highest level of the domain name system). Some could create confusion, resemble other characters too closely, or pose security risks. The MSR eliminates such characters by applying strict eligibility rules.
The updated MSR-6 is based on Unicode 16.0 and follows the established Root Zone Label Generation Rules (RZ-LGR) Procedure, which governs how scripts and languages can be safely integrated into the global domain name system.
Why this matters
IDNs make the internet more inclusive by allowing people to use domain names in their own languages and scripts. This is especially important for communities whose languages do not use the Latin alphabet, as it expands access and supports digital diversity.
A carefully curated MSR ensures that while more scripts can be supported, the system remains secure and stable, preventing potential confusion or exploitation by malicious actors.
For civil society, this consultation is an opportunity to contribute to making the internet linguistically diverse and globally accessible, while ensuring that safeguards against fraud and abuse are maintained.
How to participate
The consultation on MSR-6 is open from 17 June to 29 July 2025. The full contents and rationale for the update are available in ICANN’s MSR-6 Overview and Rationale document, and stakeholders can submit feedback through ICANN’s public comment platform.
