Public Comment Proceeding: Maximal Starting Repertoire Version 5 (MSR-5)

27 April 2021

Open Date: 27 April 2021

Close Date: 8 June 2021

Originating Organization: ICANN org – Global Domains and Strategy (GDS)


ICANN organization (ICANN org) has opened a Public Comment proceeding for the fifth version of the Maximal Starting Repertoire (MSR-5). The following documents from the MSR-5 are now available for review:

  1. MSR-5 (HTML, XML)
  2. MSR-5 Annotated-Hangul-Tables
  3. MSR-5 Annotated-Han-Tables
  4. MSR-5 Annotated-non-CJK-Tables
  5. MSR-5 Overview and Rationale

This version is upwardly compatible with MSR-4, adding one code point each to the Latin and Devanagari script repertoires, and adding two code points to the Arabic script repertoire. MSR-5 also changes the Unicode base version from 6.3 to 11.0. Under the Procedure to Develop and Maintain Label Generation Rules for the Root Zone with Respect to IDN Labels, the MSR is the starting point for the work done by community-based Generation Panels that develop Root Zone Label Generation Rules (RZ-LGR) proposals for relevant scripts. The contents of MSR-5 and a detailed rationale behind its development are available in the MSR-5 Overview and Rationale document.

Current Status

The MSR is a subset of IDNA 2008 PVALID code points for Unicode 11.0, created by following the prescriptions of Procedure to Develop and Maintain Label Generation Rules for the Root Zone with Respect to IDN Labels in eliminating code points not eligible for the root zone. The MSR is a deliverable from the Integration Panel under the procedure and serves as a starting collection of code points from which Generation Panels may make a selection in constructing the repertoire for their respective Label Generation Rules (LGR) proposals. In accordance with the procedure, "[g]eneration panels must not include in their proposed repertoires any assigned code point that is not included in the maximal set of code points for the root zone defined by the Integration Panel."

The mere presence of a code point in the MSR does not indicate that the Integration Panel considers it acceptable for inclusion in the RZ-LGR. Where the Integration Panel was not able to resolve the status of a code point, it has tended to retain it in the MSR, with the aim of allowing Generation Panels to perform a more thorough review, and where appropriate, to present a justification of the inclusion of such code points in the LGR.

In contrast, the absence of a code point affirms that the Integration Panel has determined that the code point is not appropriate for the Domain Name System (DNS) root, or in certain situations, the panel has decided to defer it to a future version of the MSR.

The Generation Panels currently use MSR-4, which covers 28 scripts: Arabic, Armenian, Bengali, Cyrillic, Devanagari, Ethiopic, Georgian, Greek, Gujarati, Gurmukhi, Han, Hangul, Hebrew, Hiragana, Kannada, Katakana, Khmer, Lao, Latin, Malayalam, Myanmar, Oriya, Sinhala, Tamil, Telugu, Thaana, Tibetan, and Thai. MSR-4 contains 33,511 code points shortlisted from 97,973 PVALID/CONTEXT code points of Unicode version 6.3.

Next Steps

MSR-5 will cover the same scripts. The Integration Panel will finalize the code point repertoire for MSR-5 based on the feedback received by the community. After the release of MSR-5, Generation Panels, which are developing their RZ-LGR proposals, will be able to use the updated contents as a starting point for their analysis.

Link to Public Comment Proceeding


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